Added modelregistry.AddRegistry

.golangci.bck.yml

@@ -0,0 +1,110 @@
+run:
+  timeout: 5m
+  tests: true
+  skip-dirs:
+    - vendor
+    - .github
+
+linters:
+  enable:
+    - errcheck
+    - gosimple
+    - govet
+    - ineffassign
+    - staticcheck
+    - unused
+    - gofmt
+    - goimports
+    - misspell
+    - gocritic
+    - revive
+    - stylecheck
+  disable:
+    - typecheck # Can cause issues with generics in some cases
+
+linters-settings:
+  errcheck:
+    check-type-assertions: false
+    check-blank: false
+
+  govet:
+    check-shadowing: false
+
+  gofmt:
+    simplify: true
+
+  goimports:
+    local-prefixes: github.com/bitechdev/ResolveSpec
+
+  gocritic:
+    enabled-checks:
+      - appendAssign
+      - assignOp
+      - boolExprSimplify
+      - builtinShadow
+      - captLocal
+      - caseOrder
+      - defaultCaseOrder
+      - dupArg
+      - dupBranchBody
+      - dupCase
+      - dupSubExpr
+      - elseif
+      - emptyFallthrough
+      - equalFold
+      - flagName
+      - ifElseChain
+      - indexAlloc
+      - initClause
+      - methodExprCall
+      - nilValReturn
+      - rangeExprCopy
+      - rangeValCopy
+      - regexpMust
+      - singleCaseSwitch
+      - sloppyLen
+      - stringXbytes
+      - switchTrue
+      - typeAssertChain
+      - typeSwitchVar
+      - underef
+      - unlabelStmt
+      - unnamedResult
+      - unnecessaryBlock
+      - weakCond
+      - yodaStyleExpr
+
+  revive:
+    rules:
+      - name: exported
+        disabled: true
+      - name: package-comments
+        disabled: true
+
+issues:
+  exclude-use-default: false
+  max-issues-per-linter: 0
+  max-same-issues: 0
+
+  # Exclude some linters from running on tests files
+  exclude-rules:
+    - path: _test\.go
+      linters:
+        - errcheck
+        - dupl
+        - gosec
+        - gocritic
+
+    # Ignore "error return value not checked" for defer statements
+    - linters:
+        - errcheck
+      text: "Error return value of .((os\\.)?std(out|err)\\..*|.*Close|.*Flush|os\\.Remove(All)?|.*print(f|ln)?|os\\.(Un)?Setenv). is not checked"
+
+    # Ignore complexity in test files
+    - path: _test\.go
+      text: "cognitive complexity|cyclomatic complexity"
+
+output:
+  format: colored-line-number
+  print-issued-lines: true
+  print-linter-name: true

.vscode/tasks.json

@@ -24,21 +24,63 @@
 			"type": "go",
 			"label": "go: test workspace",
 			"command": "test",
-			
 			"options": {
-				"env": {				
+				"cwd": "${workspaceFolder}"
-					"CGO_ENABLED": "0"
-				},
-				"cwd": "${workspaceFolder}/bin",
 			},
 			"args": [
-				"../..."
+				"-v",
+				"-race",
+				"-coverprofile=coverage.out",
+				"-covermode=atomic",
+				"./..."
 			],
 			"problemMatcher": [
 				"$go"
 			],
-			"group": "build",
+			"group": {
-			
+				"kind": "test",
+				"isDefault": true
+			},
+			"presentation": {
+				"reveal": "always",
+				"panel": "new"
+			}
 		},
+		{
+			"type": "shell",
+			"label": "go: vet workspace",
+			"command": "go vet ./...",
+			"options": {
+				"cwd": "${workspaceFolder}"
+			},
+			"problemMatcher": [
+				"$go"
+			],
+			"group": "test"
+		},
+		{
+			"type": "shell",
+			"label": "go: lint workspace",
+			"command": "golangci-lint run --timeout=5m",
+			"options": {
+				"cwd": "${workspaceFolder}"
+			},
+			"problemMatcher": [],
+			"group": "test"
+		},
+		{
+			"type": "shell",
+			"label": "go: full test suite",
+			"dependsOrder": "sequence",
+			"dependsOn": [
+				"go: vet workspace",
+				"go: test workspace"
+			],
+			"problemMatcher": [],
+			"group": {
+				"kind": "test",
+				"isDefault": false
+			}
+		}
 	]
 }

README.md

@@ -31,9 +31,12 @@ Both share the same core architecture and provide dynamic data querying, relatio
 - [RestHeadSpec: Header-Based API](#restheadspec-header-based-api-1)
   - [Lifecycle Hooks](#lifecycle-hooks)
   - [Cursor Pagination](#cursor-pagination)
+  - [Response Formats](#response-formats)
+  - [Single Record as Object](#single-record-as-object-default-behavior)
 - [Example Usage](#example-usage)
+  - [Recursive CRUD Operations](#recursive-crud-operations-)
 - [Testing](#testing)
-- [What's New in v2.0](#whats-new-in-v20)
+- [What's New](#whats-new)
 
 ## Features
 
@@ -45,6 +48,7 @@ Both share the same core architecture and provide dynamic data querying, relatio
 - **Pagination**: Built-in limit/offset and cursor-based pagination
 - **Computed Columns**: Define virtual columns for complex calculations
 - **Custom Operators**: Add custom SQL conditions when needed
+- **🆕 Recursive CRUD Handler**: Automatically handle nested object graphs with foreign key resolution and per-record operation control via `_request` field
 
 ### Architecture (v2.0+)
 - **🆕 Database Agnostic**: Works with GORM, Bun, or any database layer through adapters
@@ -57,6 +61,7 @@ Both share the same core architecture and provide dynamic data querying, relatio
 - **🆕 Lifecycle Hooks**: Before/after hooks for create, read, update, and delete operations
 - **🆕 Cursor Pagination**: Efficient cursor-based pagination with complex sort support
 - **🆕 Multiple Response Formats**: Simple, detailed, and Syncfusion-compatible formats
+- **🆕 Single Record as Object**: Automatically normalize single-element arrays to objects (enabled by default)
 - **🆕 Advanced Filtering**: Field filters, search operators, AND/OR logic, and custom SQL
 - **🆕 Base64 Encoding**: Support for base64-encoded header values
 
@@ -161,6 +166,7 @@ restheadspec.SetupMuxRoutes(router, handler)
 | `X-Limit` | Limit results | `50` |
 | `X-Offset` | Offset for pagination | `100` |
 | `X-Clean-JSON` | Remove null/empty fields | `true` |
+| `X-Single-Record-As-Object` | Return single records as objects (default: `true`) | `false` |
 
 **Available Operators**: `eq`, `neq`, `gt`, `gte`, `lt`, `lte`, `contains`, `startswith`, `endswith`, `between`, `betweeninclusive`, `in`, `empty`, `notempty`
 
@@ -301,6 +307,55 @@ RestHeadSpec supports multiple response formats:
 }
 ```
 
+### Single Record as Object (Default Behavior)
+
+By default, RestHeadSpec automatically converts single-element arrays into objects for cleaner API responses. This provides a better developer experience when fetching individual records.
+
+**Default behavior (enabled)**:
+```http
+GET /public/users/123
+```
+```json
+{
+  "success": true,
+  "data": { "id": 123, "name": "John", "email": "john@example.com" }
+}
+```
+
+Instead of:
+```json
+{
+  "success": true,
+  "data": [{ "id": 123, "name": "John", "email": "john@example.com" }]
+}
+```
+
+**To disable** (force arrays for consistency):
+```http
+GET /public/users/123
+X-Single-Record-As-Object: false
+```
+```json
+{
+  "success": true,
+  "data": [{ "id": 123, "name": "John", "email": "john@example.com" }]
+}
+```
+
+**How it works**:
+- When a query returns exactly **one record**, it's returned as an object
+- When a query returns **multiple records**, they're returned as an array
+- Set `X-Single-Record-As-Object: false` to always receive arrays
+- Works with all response formats (simple, detail, syncfusion)
+- Applies to both read operations and create/update returning clauses
+
+**Benefits**:
+- Cleaner API responses for single-record queries
+- No need to unwrap single-element arrays on the client side
+- Better TypeScript/type inference support
+- Consistent with common REST API patterns
+- Backward compatible via header opt-out
+
 ## Example Usage
 
 ### Reading Data with Related Entities
@@ -342,6 +397,92 @@ POST /core/users
 }
 ```
 
+### Recursive CRUD Operations (🆕)
+
+ResolveSpec now supports automatic handling of nested object graphs with intelligent foreign key resolution. This allows you to create, update, or delete entire object hierarchies in a single request.
+
+#### Creating Nested Objects
+
+```json
+POST /core/users
+{
+  "operation": "create",
+  "data": {
+    "name": "John Doe",
+    "email": "john@example.com",
+    "posts": [
+      {
+        "title": "My First Post",
+        "content": "Hello World",
+        "tags": [
+          {"name": "tech"},
+          {"name": "programming"}
+        ]
+      },
+      {
+        "title": "Second Post",
+        "content": "More content"
+      }
+    ],
+    "profile": {
+      "bio": "Software Developer",
+      "website": "https://example.com"
+    }
+  }
+}
+```
+
+#### Per-Record Operation Control with `_request`
+
+Control individual operations for each nested record using the special `_request` field:
+
+```json
+POST /core/users/123
+{
+  "operation": "update",
+  "data": {
+    "name": "John Updated",
+    "posts": [
+      {
+        "_request": "insert",
+        "title": "New Post",
+        "content": "Fresh content"
+      },
+      {
+        "_request": "update",
+        "id": 456,
+        "title": "Updated Post Title"
+      },
+      {
+        "_request": "delete",
+        "id": 789
+      }
+    ]
+  }
+}
+```
+
+**Supported `_request` values**:
+- `insert` - Create a new related record
+- `update` - Update an existing related record
+- `delete` - Delete a related record
+- `upsert` - Create if doesn't exist, update if exists
+
+#### How It Works
+
+1. **Automatic Foreign Key Resolution**: Parent IDs are automatically propagated to child records
+2. **Recursive Processing**: Handles nested relationships at any depth
+3. **Transaction Safety**: All operations execute within database transactions
+4. **Relationship Detection**: Automatically detects belongsTo, hasMany, hasOne, and many2many relationships
+5. **Flexible Operations**: Mix create, update, and delete operations in a single request
+
+#### Benefits
+
+- Reduce API round trips for complex object graphs
+- Maintain referential integrity automatically
+- Simplify client-side code
+- Atomic operations with automatic rollback on errors
+
 ## Installation
 
 ```bash
@@ -811,12 +952,32 @@ This project is licensed under the MIT License - see the [LICENSE](LICENSE) file
 
 ### v2.1 (Latest)
 
+**Recursive CRUD Handler (🆕 Nov 11, 2025)**:
+- **Nested Object Graphs**: Automatically handle complex object hierarchies with parent-child relationships
+- **Foreign Key Resolution**: Automatic propagation of parent IDs to child records
+- **Per-Record Operations**: Control create/update/delete operations per record via `_request` field
+- **Transaction Safety**: All nested operations execute atomically within database transactions
+- **Relationship Detection**: Automatic detection of belongsTo, hasMany, hasOne, and many2many relationships
+- **Deep Nesting Support**: Handle relationships at any depth level
+- **Mixed Operations**: Combine insert, update, and delete operations in a single request
+
+**Primary Key Improvements (Nov 11, 2025)**:
+- **GetPrimaryKeyName**: Enhanced primary key detection for better preload and ID field handling
+- **Better GORM/Bun Support**: Improved compatibility with both ORMs for primary key operations
+- **Computed Column Support**: Fixed computed columns functionality across handlers
+
+**Database Adapter Enhancements (Nov 11, 2025)**:
+- **Bun ORM Relations**: Using Scan model method for better has-many and many-to-many relationship handling
+- **Model Method Support**: Enhanced query building with proper model registration
+- **Improved Type Safety**: Better handling of relationship queries with type-aware scanning
+
 **RestHeadSpec - Header-Based REST API**:
 - **Header-Based Querying**: All query options via HTTP headers instead of request body
 - **Lifecycle Hooks**: Before/after hooks for create, read, update, delete operations
 - **Cursor Pagination**: Efficient cursor-based pagination with complex sorting
 - **Advanced Filtering**: Field filters, search operators, AND/OR logic
 - **Multiple Response Formats**: Simple, detailed, and Syncfusion-compatible responses
+- **Single Record as Object**: Automatically return single-element arrays as objects (default, toggleable via header)
 - **Base64 Support**: Base64-encoded header values for complex queries
 - **Type-Aware Filtering**: Automatic type detection and conversion for filters
 
@@ -826,6 +987,7 @@ This project is licensed under the MIT License - see the [LICENSE](LICENSE) file
 - Improved reflection safety
 - Fixed COUNT query issues with table aliasing
 - Better pointer handling throughout the codebase
+- **Comprehensive Test Coverage**: Added standalone CRUD tests for both ResolveSpec and RestHeadSpec
 
 ### v2.0
 

pkg/common/adapters/database/bun.go

@@ -9,6 +9,8 @@ import (
 	"github.com/uptrace/bun"
 
 	"github.com/bitechdev/ResolveSpec/pkg/common"
+	"github.com/bitechdev/ResolveSpec/pkg/modelregistry"
+	"github.com/bitechdev/ResolveSpec/pkg/reflection"
 )
 
 // BunAdapter adapts Bun to work with our Database interface
@@ -215,6 +217,40 @@ func (b *BunSelectQuery) Preload(relation string, conditions ...interface{}) com
 	return b
 }
 
+func (b *BunSelectQuery) PreloadRelation(relation string, apply ...func(common.SelectQuery) common.SelectQuery) common.SelectQuery {
+	b.query = b.query.Relation(relation, func(sq *bun.SelectQuery) *bun.SelectQuery {
+		if len(apply) == 0 {
+			return sq
+		}
+
+		// Wrap the incoming *bun.SelectQuery in our adapter
+		wrapper := &BunSelectQuery{
+			query: sq,
+			db:    b.db,
+		}
+
+		// Start with the interface value (not pointer)
+		current := common.SelectQuery(wrapper)
+
+		// Apply each function in sequence
+		for _, fn := range apply {
+			if fn != nil {
+				// Pass &current (pointer to interface variable), fn modifies and returns new interface value
+				modified := fn(current)
+				current = modified
+			}
+		}
+
+		// Extract the final *bun.SelectQuery
+		if finalBun, ok := current.(*BunSelectQuery); ok {
+			return finalBun.query
+		}
+
+		return sq // fallback
+	})
+	return b
+}
+
 func (b *BunSelectQuery) Order(order string) common.SelectQuery {
 	b.query = b.query.Order(order)
 	return b
@@ -319,25 +355,45 @@ func (b *BunInsertQuery) Exec(ctx context.Context) (common.Result, error) {
 // BunUpdateQuery implements UpdateQuery for Bun
 type BunUpdateQuery struct {
 	query *bun.UpdateQuery
+	model interface{}
 }
 
 func (b *BunUpdateQuery) Model(model interface{}) common.UpdateQuery {
 	b.query = b.query.Model(model)
+	b.model = model
 	return b
 }
 
 func (b *BunUpdateQuery) Table(table string) common.UpdateQuery {
 	b.query = b.query.Table(table)
+	if b.model == nil {
+		// Try to get table name from table string if model is not set
+
+		model, err := modelregistry.GetModelByName(table)
+		if err == nil {
+			b.model = model
+		}
+	}
 	return b
 }
 
 func (b *BunUpdateQuery) Set(column string, value interface{}) common.UpdateQuery {
+	// Validate column is writable if model is set
+	if b.model != nil && !reflection.IsColumnWritable(b.model, column) {
+		// Skip scan-only columns
+		return b
+	}
 	b.query = b.query.Set(column+" = ?", value)
 	return b
 }
 
 func (b *BunUpdateQuery) SetMap(values map[string]interface{}) common.UpdateQuery {
 	for column, value := range values {
+		// Validate column is writable if model is set
+		if b.model != nil && !reflection.IsColumnWritable(b.model, column) {
+			// Skip scan-only columns
+			continue
+		}
 		b.query = b.query.Set(column+" = ?", value)
 	}
 	return b

pkg/common/adapters/database/gorm.go

@@ -8,6 +8,8 @@ import (
 	"gorm.io/gorm"
 
 	"github.com/bitechdev/ResolveSpec/pkg/common"
+	"github.com/bitechdev/ResolveSpec/pkg/modelregistry"
+	"github.com/bitechdev/ResolveSpec/pkg/reflection"
 )
 
 // GormAdapter adapts GORM to work with our Database interface
@@ -97,6 +99,7 @@ func (g *GormSelectQuery) Table(table string) common.SelectQuery {
 	g.db = g.db.Table(table)
 	// Check if the table name contains schema (e.g., "schema.table")
 	g.schema, g.tableName = parseTableName(table)
+
 	return g
 }
 
@@ -197,6 +200,36 @@ func (g *GormSelectQuery) Preload(relation string, conditions ...interface{}) co
 	return g
 }
 
+func (g *GormSelectQuery) PreloadRelation(relation string, apply ...func(common.SelectQuery) common.SelectQuery) common.SelectQuery {
+	g.db = g.db.Preload(relation, func(db *gorm.DB) *gorm.DB {
+		if len(apply) == 0 {
+			return db
+		}
+
+		wrapper := &GormSelectQuery{
+			db: db,
+		}
+
+		current := common.SelectQuery(wrapper)
+
+		for _, fn := range apply {
+			if fn != nil {
+
+				modified := fn(current)
+				current = modified
+			}
+		}
+
+		if finalBun, ok := current.(*GormSelectQuery); ok {
+			return finalBun.db
+		}
+
+		return db // fallback
+	})
+
+	return g
+}
+
 func (g *GormSelectQuery) Order(order string) common.SelectQuery {
 	g.db = g.db.Order(order)
 	return g
@@ -309,10 +342,23 @@ func (g *GormUpdateQuery) Model(model interface{}) common.UpdateQuery {
 
 func (g *GormUpdateQuery) Table(table string) common.UpdateQuery {
 	g.db = g.db.Table(table)
+	if g.model == nil {
+		// Try to get table name from table string if model is not set
+		model, err := modelregistry.GetModelByName(table)
+		if err == nil {
+			g.model = model
+		}
+	}
 	return g
 }
 
 func (g *GormUpdateQuery) Set(column string, value interface{}) common.UpdateQuery {
+	// Validate column is writable if model is set
+	if g.model != nil && !reflection.IsColumnWritable(g.model, column) {
+		// Skip read-only columns
+		return g
+	}
+
 	if g.updates == nil {
 		g.updates = make(map[string]interface{})
 	}
@@ -323,7 +369,18 @@ func (g *GormUpdateQuery) Set(column string, value interface{}) common.UpdateQue
 }
 
 func (g *GormUpdateQuery) SetMap(values map[string]interface{}) common.UpdateQuery {
-	g.updates = values
+	// Filter out read-only columns if model is set
+	if g.model != nil {
+		filteredValues := make(map[string]interface{})
+		for column, value := range values {
+			if reflection.IsColumnWritable(g.model, column) {
+				filteredValues[column] = value
+			}
+		}
+		g.updates = filteredValues
+	} else {
+		g.updates = values
+	}
 	return g
 }
 

pkg/common/adapters/database/update_validation_test.go

@@ -0,0 +1,161 @@
+package database
+
+import (
+	"testing"
+
+	"github.com/bitechdev/ResolveSpec/pkg/reflection"
+)
+
+// Test models for bun
+type BunTestModel struct {
+	ID          int    `bun:"id,pk"`
+	Name        string `bun:"name"`
+	Email       string `bun:"email"`
+	ComputedCol string `bun:"computed_col,scanonly"`
+}
+
+// Test models for gorm
+type GormTestModel struct {
+	ID          int    `gorm:"column:id;primaryKey"`
+	Name        string `gorm:"column:name"`
+	Email       string `gorm:"column:email"`
+	ReadOnlyCol string `gorm:"column:readonly_col;->"`
+	NoWriteCol  string `gorm:"column:nowrite_col;<-:false"`
+}
+
+func TestIsColumnWritable_Bun(t *testing.T) {
+	model := &BunTestModel{}
+
+	tests := []struct {
+		name       string
+		columnName string
+		expected   bool
+	}{
+		{
+			name:       "writable column - id",
+			columnName: "id",
+			expected:   true,
+		},
+		{
+			name:       "writable column - name",
+			columnName: "name",
+			expected:   true,
+		},
+		{
+			name:       "writable column - email",
+			columnName: "email",
+			expected:   true,
+		},
+		{
+			name:       "scanonly column should not be writable",
+			columnName: "computed_col",
+			expected:   false,
+		},
+		{
+			name:       "non-existent column should be writable (dynamic)",
+			columnName: "nonexistent",
+			expected:   true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := reflection.IsColumnWritable(model, tt.columnName)
+			if result != tt.expected {
+				t.Errorf("IsColumnWritable(%q) = %v, want %v", tt.columnName, result, tt.expected)
+			}
+		})
+	}
+}
+
+func TestIsColumnWritable_Gorm(t *testing.T) {
+	model := &GormTestModel{}
+
+	tests := []struct {
+		name       string
+		columnName string
+		expected   bool
+	}{
+		{
+			name:       "writable column - id",
+			columnName: "id",
+			expected:   true,
+		},
+		{
+			name:       "writable column - name",
+			columnName: "name",
+			expected:   true,
+		},
+		{
+			name:       "writable column - email",
+			columnName: "email",
+			expected:   true,
+		},
+		{
+			name:       "read-only column with -> should not be writable",
+			columnName: "readonly_col",
+			expected:   false,
+		},
+		{
+			name:       "column with <-:false should not be writable",
+			columnName: "nowrite_col",
+			expected:   false,
+		},
+		{
+			name:       "non-existent column should be writable (dynamic)",
+			columnName: "nonexistent",
+			expected:   true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := reflection.IsColumnWritable(model, tt.columnName)
+			if result != tt.expected {
+				t.Errorf("IsColumnWritable(%q) = %v, want %v", tt.columnName, result, tt.expected)
+			}
+		})
+	}
+}
+
+func TestBunUpdateQuery_SetMap_FiltersScanOnly(t *testing.T) {
+	// Note: This is a unit test for the validation logic only.
+	// We can't fully test the bun query without a database connection,
+	// but we've verified the validation logic in TestIsColumnWritable_Bun
+	t.Skip("Skipping integration test - validation logic tested in TestIsColumnWritable_Bun")
+}
+
+func TestGormUpdateQuery_SetMap_FiltersReadOnly(t *testing.T) {
+	model := &GormTestModel{}
+	query := &GormUpdateQuery{
+		model: model,
+	}
+
+	// SetMap should filter out read-only columns
+	values := map[string]interface{}{
+		"name":         "John",
+		"email":        "john@example.com",
+		"readonly_col": "should_be_filtered",
+		"nowrite_col":  "should_also_be_filtered",
+	}
+
+	query.SetMap(values)
+
+	// Check that the updates map only contains writable columns
+	if updates, ok := query.updates.(map[string]interface{}); ok {
+		if _, exists := updates["readonly_col"]; exists {
+			t.Error("readonly_col should have been filtered out")
+		}
+		if _, exists := updates["nowrite_col"]; exists {
+			t.Error("nowrite_col should have been filtered out")
+		}
+		if _, exists := updates["name"]; !exists {
+			t.Error("name should be in updates")
+		}
+		if _, exists := updates["email"]; !exists {
+			t.Error("email should be in updates")
+		}
+	} else {
+		t.Error("updates should be a map[string]interface{}")
+	}
+}

pkg/common/interfaces.go

@@ -32,6 +32,7 @@ type SelectQuery interface {
 	Join(query string, args ...interface{}) SelectQuery
 	LeftJoin(query string, args ...interface{}) SelectQuery
 	Preload(relation string, conditions ...interface{}) SelectQuery
+	PreloadRelation(relation string, apply ...func(SelectQuery) SelectQuery) SelectQuery
 	Order(order string) SelectQuery
 	Limit(n int) SelectQuery
 	Offset(n int) SelectQuery

pkg/common/recursive_crud.go

@@ -7,6 +7,7 @@ import (
 	"strings"
 
 	"github.com/bitechdev/ResolveSpec/pkg/logger"
+	"github.com/bitechdev/ResolveSpec/pkg/reflection"
 )
 
 // CRUDRequestProvider interface for models that provide CRUD request strings
@@ -248,7 +249,7 @@ func (p *NestedCUDProcessor) processUpdate(
 
 	logger.Debug("Updating %s with ID %v, data: %+v", tableName, id, data)
 
-	query := p.db.NewUpdate().Table(tableName).SetMap(data).Where("id = ?", id)
+	query := p.db.NewUpdate().Table(tableName).SetMap(data).Where(fmt.Sprintf("%s = ?", QuoteIdent(reflection.GetPrimaryKeyName(tableName))), id)
 
 	result, err := query.Exec(ctx)
 	if err != nil {
@@ -268,7 +269,7 @@ func (p *NestedCUDProcessor) processDelete(ctx context.Context, tableName string
 
 	logger.Debug("Deleting from %s with ID %v", tableName, id)
 
-	query := p.db.NewDelete().Table(tableName).Where("id = ?", id)
+	query := p.db.NewDelete().Table(tableName).Where(fmt.Sprintf("%s = ?", QuoteIdent(reflection.GetPrimaryKeyName(tableName))), id)
 
 	result, err := query.Exec(ctx)
 	if err != nil {
@@ -377,8 +378,16 @@ func (p *NestedCUDProcessor) getTableNameForModel(model interface{}, defaultName
 }
 
 // ShouldUseNestedProcessor determines if we should use nested CUD processing
-// It checks if the data contains nested relations or a _request field
+// It recursively checks if the data contains:
+// 1. A _request field at any level, OR
+// 2. Nested relations that themselves contain further nested relations or _request fields
+// This ensures nested processing is only used when there are deeply nested operations
 func ShouldUseNestedProcessor(data map[string]interface{}, model interface{}, relationshipHelper RelationshipInfoProvider) bool {
+	return shouldUseNestedProcessorDepth(data, model, relationshipHelper, 0)
+}
+
+// shouldUseNestedProcessorDepth is the internal recursive implementation with depth tracking
+func shouldUseNestedProcessorDepth(data map[string]interface{}, model interface{}, relationshipHelper RelationshipInfoProvider, depth int) bool {
 	// Check for _request field
 	if _, hasCRUDRequest := data["_request"]; hasCRUDRequest {
 		return true
@@ -405,10 +414,34 @@ func ShouldUseNestedProcessor(data map[string]interface{}, model interface{}, re
 		relInfo := relationshipHelper.GetRelationshipInfo(modelType, key)
 		if relInfo != nil {
 			// Check if the value is actually nested data (object or array)
-			switch value.(type) {
+			switch v := value.(type) {
 			case map[string]interface{}, []interface{}, []map[string]interface{}:
-				logger.Debug("Found nested relation field: %s", key)
+				// If we're already at a nested level (depth > 0) and found a relation,
-				return true
+				// that means we have multi-level nesting, so return true
+				if depth > 0 {
+					return true
+				}
+				// At depth 0, recurse to check if the nested data has further nesting
+				switch typedValue := v.(type) {
+				case map[string]interface{}:
+					if shouldUseNestedProcessorDepth(typedValue, relInfo.RelatedModel, relationshipHelper, depth+1) {
+						return true
+					}
+				case []interface{}:
+					for _, item := range typedValue {
+						if itemMap, ok := item.(map[string]interface{}); ok {
+							if shouldUseNestedProcessorDepth(itemMap, relInfo.RelatedModel, relationshipHelper, depth+1) {
+								return true
+							}
+						}
+					}
+				case []map[string]interface{}:
+					for _, itemMap := range typedValue {
+						if shouldUseNestedProcessorDepth(itemMap, relInfo.RelatedModel, relationshipHelper, depth+1) {
+							return true
+						}
+					}
+				}
 			}
 		}
 	}

pkg/common/types.go

@@ -35,7 +35,9 @@ type PreloadOption struct {
 	Relation    string         `json:"relation"`
 	Columns     []string       `json:"columns"`
 	OmitColumns []string       `json:"omit_columns"`
+	Sort        []SortOption   `json:"sort"`
 	Filters     []FilterOption `json:"filters"`
+	Where       string         `json:"where"`
 	Limit       *int           `json:"limit"`
 	Offset      *int           `json:"offset"`
 	Updatable   *bool          `json:"updateable"` // if true, the relation can be updated

pkg/common/validation.go

@@ -183,7 +183,8 @@ func (v *ColumnValidator) ValidateRequestOptions(options RequestOptions) error {
 	}
 
 	// Validate Preload columns (if specified)
-	for _, preload := range options.Preload {
+	for idx := range options.Preload {
+		preload := options.Preload[idx]
 		// Note: We don't validate the relation name itself, as it's a relationship
 		// Only validate columns if specified for the preload
 		if err := v.ValidateColumns(preload.Columns); err != nil {
@@ -239,7 +240,8 @@ func (v *ColumnValidator) FilterRequestOptions(options RequestOptions) RequestOp
 
 	// Filter Preload columns
 	validPreloads := make([]PreloadOption, 0, len(options.Preload))
-	for _, preload := range options.Preload {
+	for idx := range options.Preload {
+		preload := options.Preload[idx]
 		filteredPreload := preload
 		filteredPreload.Columns = v.FilterValidColumns(preload.Columns)
 		filteredPreload.OmitColumns = v.FilterValidColumns(preload.OmitColumns)
@@ -270,3 +272,11 @@ func (v *ColumnValidator) GetValidColumns() []string {
 	}
 	return columns
 }
+
+func QuoteIdent(qualifier string) string {
+	return `"` + strings.ReplaceAll(qualifier, `"`, `""`) + `"`
+}
+
+func QuoteLiteral(value string) string {
+	return `'` + strings.ReplaceAll(value, `'`, `''`) + `'`
+}

pkg/modelregistry/model_registry.go

@@ -17,6 +17,10 @@ var defaultRegistry = &DefaultModelRegistry{
 	models: make(map[string]interface{}),
 }
 
+// Global list of registries (searched in order)
+var registries = []*DefaultModelRegistry{defaultRegistry}
+var registriesMutex sync.RWMutex
+
 // NewModelRegistry creates a new model registry
 func NewModelRegistry() *DefaultModelRegistry {
 	return &DefaultModelRegistry{
@@ -24,6 +28,14 @@ func NewModelRegistry() *DefaultModelRegistry {
 	}
 }
 
+// AddRegistry adds a registry to the global list of registries
+// Registries are searched in the order they were added
+func AddRegistry(registry *DefaultModelRegistry) {
+	registriesMutex.Lock()
+	defer registriesMutex.Unlock()
+	registries = append(registries, registry)
+}
+
 func (r *DefaultModelRegistry) RegisterModel(name string, model interface{}) error {
 	r.mutex.Lock()
 	defer r.mutex.Unlock()
@@ -107,9 +119,19 @@ func RegisterModel(model interface{}, name string) error {
 	return defaultRegistry.RegisterModel(name, model)
 }
 
-// GetModelByName retrieves a model from the default global registry by name
+// GetModelByName retrieves a model by searching through all registries in order
+// Returns the first match found
 func GetModelByName(name string) (interface{}, error) {
-	return defaultRegistry.GetModel(name)
+	registriesMutex.RLock()
+	defer registriesMutex.RUnlock()
+
+	for _, registry := range registries {
+		if model, err := registry.GetModel(name); err == nil {
+			return model, nil
+		}
+	}
+
+	return nil, fmt.Errorf("model %s not found in any registry", name)
 }
 
 // IterateModels iterates over all models in the default global registry
@@ -122,14 +144,26 @@ func IterateModels(fn func(name string, model interface{})) {
 	}
 }
 
-// GetModels returns a list of all models in the default global registry
+// GetModels returns a list of all models from all registries
+// Models are collected in registry order, with duplicates included
 func GetModels() []interface{} {
-	defaultRegistry.mutex.RLock()
+	registriesMutex.RLock()
-	defer defaultRegistry.mutex.RUnlock()
+	defer registriesMutex.RUnlock()
 
-	models := make([]interface{}, 0, len(defaultRegistry.models))
+	var models []interface{}
-	for _, model := range defaultRegistry.models {
+	seen := make(map[string]bool)
-		models = append(models, model)
+
+	for _, registry := range registries {
+		registry.mutex.RLock()
+		for name, model := range registry.models {
+			// Only add the first occurrence of each model name
+			if !seen[name] {
+				models = append(models, model)
+				seen[name] = true
+			}
+		}
+		registry.mutex.RUnlock()
 	}
+
 	return models
 }

pkg/reflection/helpers.go

@@ -1,9 +1,15 @@
-package common
+package reflection
 
 import "reflect"
 
 func Len(v any) int {
 	val := reflect.ValueOf(v)
+	valKind := val.Kind()
+
+	if valKind == reflect.Ptr {
+		val = val.Elem()
+	}
+
 	switch val.Kind() {
 	case reflect.Slice, reflect.Array, reflect.Map, reflect.String, reflect.Chan:
 		return val.Len()

pkg/reflection/model_utils.go

@@ -4,15 +4,31 @@ import (
 	"reflect"
 	"strings"
 
-	"github.com/bitechdev/ResolveSpec/pkg/common"
+	"github.com/bitechdev/ResolveSpec/pkg/modelregistry"
 )
 
+type PrimaryKeyNameProvider interface {
+	GetIDName() string
+}
+
 // GetPrimaryKeyName extracts the primary key column name from a model
 // It first checks if the model implements PrimaryKeyNameProvider (GetIDName method)
 // Falls back to reflection to find bun:",pk" tag, then gorm:"primaryKey" tag
 func GetPrimaryKeyName(model any) string {
+	if reflect.TypeOf(model) == nil {
+		return ""
+	}
+	// If we are given a string model name, look up the model
+	if reflect.TypeOf(model).Kind() == reflect.String {
+		name := model.(string)
+		m, err := modelregistry.GetModelByName(name)
+		if err == nil {
+			model = m
+		}
+	}
+
 	// Check if model implements PrimaryKeyNameProvider
-	if provider, ok := model.(common.PrimaryKeyNameProvider); ok {
+	if provider, ok := model.(PrimaryKeyNameProvider); ok {
 		return provider.GetIDName()
 	}
 
@@ -22,7 +38,67 @@ func GetPrimaryKeyName(model any) string {
 	}
 
 	// Fall back to GORM tag
-	return getPrimaryKeyFromReflection(model, "gorm")
+	if pkName := getPrimaryKeyFromReflection(model, "gorm"); pkName != "" {
+		return pkName
+	}
+
+	return ""
+}
+
+// GetPrimaryKeyValue extracts the primary key value from a model instance
+// Returns the value of the primary key field
+func GetPrimaryKeyValue(model any) interface{} {
+	if model == nil || reflect.TypeOf(model) == nil {
+		return nil
+	}
+
+	val := reflect.ValueOf(model)
+	if val.Kind() == reflect.Pointer {
+		val = val.Elem()
+	}
+
+	if val.Kind() != reflect.Struct {
+		return nil
+	}
+
+	typ := val.Type()
+
+	// Try Bun tag first
+	for i := 0; i < typ.NumField(); i++ {
+		field := typ.Field(i)
+		bunTag := field.Tag.Get("bun")
+		if strings.Contains(bunTag, "pk") {
+			fieldValue := val.Field(i)
+			if fieldValue.CanInterface() {
+				return fieldValue.Interface()
+			}
+		}
+	}
+
+	// Fall back to GORM tag
+	for i := 0; i < typ.NumField(); i++ {
+		field := typ.Field(i)
+		gormTag := field.Tag.Get("gorm")
+		if strings.Contains(gormTag, "primaryKey") {
+			fieldValue := val.Field(i)
+			if fieldValue.CanInterface() {
+				return fieldValue.Interface()
+			}
+		}
+	}
+
+	// Last resort: look for field named "ID" or "Id"
+	for i := 0; i < typ.NumField(); i++ {
+		field := typ.Field(i)
+		if strings.ToLower(field.Name) == "id" {
+			fieldValue := val.Field(i)
+			if fieldValue.CanInterface() {
+				return fieldValue.Interface()
+			}
+		}
+	}
+
+	return nil
 }
 
 // GetModelColumns extracts all column names from a model using reflection
@@ -160,3 +236,90 @@ func ExtractColumnFromBunTag(tag string) string {
 	}
 	return ""
 }
+
+// IsColumnWritable checks if a column can be written to in the database
+// For bun: returns false if the field has "scanonly" tag
+// For gorm: returns false if the field has "<-:false" or "->" (read-only) tag
+func IsColumnWritable(model any, columnName string) bool {
+	modelType := reflect.TypeOf(model)
+
+	// Unwrap pointers to get to the base struct type
+	for modelType != nil && modelType.Kind() == reflect.Pointer {
+		modelType = modelType.Elem()
+	}
+
+	// Validate that we have a struct type
+	if modelType == nil || modelType.Kind() != reflect.Struct {
+		return false
+	}
+
+	for i := 0; i < modelType.NumField(); i++ {
+		field := modelType.Field(i)
+
+		// Check if this field matches the column name
+		fieldColumnName := getColumnNameFromField(field)
+		if fieldColumnName != columnName {
+			continue
+		}
+
+		// Check bun tag for scanonly
+		bunTag := field.Tag.Get("bun")
+		if bunTag != "" {
+			if isBunFieldScanOnly(bunTag) {
+				return false
+			}
+		}
+
+		// Check gorm tag for write restrictions
+		gormTag := field.Tag.Get("gorm")
+		if gormTag != "" {
+			if isGormFieldReadOnly(gormTag) {
+				return false
+			}
+		}
+
+		// Column is writable
+		return true
+	}
+
+	// Column not found in model, allow it (might be a dynamic column)
+	return true
+}
+
+// isBunFieldScanOnly checks if a bun tag indicates the field is scan-only
+// Example: "column_name,scanonly" -> true
+func isBunFieldScanOnly(tag string) bool {
+	parts := strings.Split(tag, ",")
+	for _, part := range parts {
+		if strings.TrimSpace(part) == "scanonly" {
+			return true
+		}
+	}
+	return false
+}
+
+// isGormFieldReadOnly checks if a gorm tag indicates the field is read-only
+// Examples:
+//   - "<-:false" -> true (no writes allowed)
+//   - "->" -> true (read-only, common pattern)
+//   - "column:name;->" -> true
+//   - "<-:create" -> false (writes allowed on create)
+func isGormFieldReadOnly(tag string) bool {
+	parts := strings.Split(tag, ";")
+	for _, part := range parts {
+		part = strings.TrimSpace(part)
+
+		// Check for read-only marker
+		if part == "->" {
+			return true
+		}
+
+		// Check for write restrictions
+		if value, found := strings.CutPrefix(part, "<-:"); found {
+			if value == "false" {
+				return true
+			}
+		}
+	}
+	return false
+}

pkg/resolvespec/handler.go

@@ -11,6 +11,7 @@ import (
 
 	"github.com/bitechdev/ResolveSpec/pkg/common"
 	"github.com/bitechdev/ResolveSpec/pkg/logger"
+	"github.com/bitechdev/ResolveSpec/pkg/reflection"
 )
 
 // Handler handles API requests using database and model abstractions
@@ -199,7 +200,7 @@ func (h *Handler) handleRead(ctx context.Context, w common.ResponseWriter, id st
 	if len(options.ComputedColumns) > 0 {
 		for _, cu := range options.ComputedColumns {
 			logger.Debug("Applying computed column: %s", cu.Name)
-			query = query.ColumnExpr("(?) AS "+cu.Name, cu.Expression)
+			query = query.ColumnExpr(fmt.Sprintf("(%s) AS %s", cu.Expression, cu.Name))
 		}
 	}
 
@@ -249,7 +250,8 @@ func (h *Handler) handleRead(ctx context.Context, w common.ResponseWriter, id st
 		logger.Debug("Querying single record with ID: %s", id)
 		// For single record, create a new pointer to the struct type
 		singleResult := reflect.New(modelType).Interface()
-		query = query.Where("id = ?", id)
+
+		query = query.Where(fmt.Sprintf("%s = ?", common.QuoteIdent(reflection.GetPrimaryKeyName(singleResult))), id)
 		if err := query.Scan(ctx, singleResult); err != nil {
 			logger.Error("Error querying record: %v", err)
 			h.sendError(w, http.StatusInternalServerError, "query_error", "Error executing query", err)
@@ -521,15 +523,15 @@ func (h *Handler) handleUpdate(ctx context.Context, w common.ResponseWriter, url
 		// Apply conditions
 		if urlID != "" {
 			logger.Debug("Updating by URL ID: %s", urlID)
-			query = query.Where("id = ?", urlID)
+			query = query.Where(fmt.Sprintf("%s = ?", common.QuoteIdent(reflection.GetPrimaryKeyName(model))), urlID)
 		} else if reqID != nil {
 			switch id := reqID.(type) {
 			case string:
 				logger.Debug("Updating by request ID: %s", id)
-				query = query.Where("id = ?", id)
+				query = query.Where(fmt.Sprintf("%s = ?", common.QuoteIdent(reflection.GetPrimaryKeyName(model))), id)
 			case []string:
 				logger.Debug("Updating by multiple IDs: %v", id)
-				query = query.Where("id IN (?)", id)
+				query = query.Where(fmt.Sprintf("%s IN (?)", common.QuoteIdent(reflection.GetPrimaryKeyName(model))), id)
 			}
 		}
 
@@ -593,7 +595,8 @@ func (h *Handler) handleUpdate(ctx context.Context, w common.ResponseWriter, url
 		err := h.db.RunInTransaction(ctx, func(tx common.Database) error {
 			for _, item := range updates {
 				if itemID, ok := item["id"]; ok {
-					txQuery := tx.NewUpdate().Table(tableName).SetMap(item).Where("id = ?", itemID)
+
+					txQuery := tx.NewUpdate().Table(tableName).SetMap(item).Where(fmt.Sprintf("%s = ?", common.QuoteIdent(reflection.GetPrimaryKeyName(model))), itemID)
 					if _, err := txQuery.Exec(ctx); err != nil {
 						return err
 					}
@@ -659,7 +662,8 @@ func (h *Handler) handleUpdate(ctx context.Context, w common.ResponseWriter, url
 			for _, item := range updates {
 				if itemMap, ok := item.(map[string]interface{}); ok {
 					if itemID, ok := itemMap["id"]; ok {
-						txQuery := tx.NewUpdate().Table(tableName).SetMap(itemMap).Where("id = ?", itemID)
+
+						txQuery := tx.NewUpdate().Table(tableName).SetMap(itemMap).Where(fmt.Sprintf("%s = ?", common.QuoteIdent(reflection.GetPrimaryKeyName(model))), itemID)
 						if _, err := txQuery.Exec(ctx); err != nil {
 							return err
 						}
@@ -695,6 +699,7 @@ func (h *Handler) handleDelete(ctx context.Context, w common.ResponseWriter, id
 	schema := GetSchema(ctx)
 	entity := GetEntity(ctx)
 	tableName := GetTableName(ctx)
+	model := GetModel(ctx)
 
 	logger.Info("Deleting records from %s.%s", schema, entity)
 
@@ -706,7 +711,8 @@ func (h *Handler) handleDelete(ctx context.Context, w common.ResponseWriter, id
 			logger.Info("Batch delete with %d IDs ([]string)", len(v))
 			err := h.db.RunInTransaction(ctx, func(tx common.Database) error {
 				for _, itemID := range v {
-					query := tx.NewDelete().Table(tableName).Where("id = ?", itemID)
+
+					query := tx.NewDelete().Table(tableName).Where(fmt.Sprintf("%s = ?", common.QuoteIdent(reflection.GetPrimaryKeyName(model))), itemID)
 					if _, err := query.Exec(ctx); err != nil {
 						return fmt.Errorf("failed to delete record %s: %w", itemID, err)
 					}
@@ -745,7 +751,7 @@ func (h *Handler) handleDelete(ctx context.Context, w common.ResponseWriter, id
 						continue // Skip items without ID
 					}
 
-					query := tx.NewDelete().Table(tableName).Where("id = ?", itemID)
+					query := tx.NewDelete().Table(tableName).Where(fmt.Sprintf("%s = ?", common.QuoteIdent(reflection.GetPrimaryKeyName(model))), itemID)
 					result, err := query.Exec(ctx)
 					if err != nil {
 						return fmt.Errorf("failed to delete record %v: %w", itemID, err)
@@ -770,7 +776,7 @@ func (h *Handler) handleDelete(ctx context.Context, w common.ResponseWriter, id
 			err := h.db.RunInTransaction(ctx, func(tx common.Database) error {
 				for _, item := range v {
 					if itemID, ok := item["id"]; ok && itemID != nil {
-						query := tx.NewDelete().Table(tableName).Where("id = ?", itemID)
+						query := tx.NewDelete().Table(tableName).Where(fmt.Sprintf("%s = ?", common.QuoteIdent(reflection.GetPrimaryKeyName(model))), itemID)
 						result, err := query.Exec(ctx)
 						if err != nil {
 							return fmt.Errorf("failed to delete record %v: %w", itemID, err)
@@ -804,7 +810,7 @@ func (h *Handler) handleDelete(ctx context.Context, w common.ResponseWriter, id
 		return
 	}
 
-	query := h.db.NewDelete().Table(tableName).Where("id = ?", id)
+	query := h.db.NewDelete().Table(tableName).Where(fmt.Sprintf("%s = ?", common.QuoteIdent(reflection.GetPrimaryKeyName(model))), id)
 
 	result, err := query.Exec(ctx)
 	if err != nil {
@@ -1113,7 +1119,8 @@ func (h *Handler) applyPreloads(model interface{}, query common.SelectQuery, pre
 		return query
 	}
 
-	for _, preload := range preloads {
+	for idx := range preloads {
+		preload := preloads[idx]
 		logger.Debug("Processing preload for relation: %s", preload.Relation)
 		relInfo := h.getRelationshipInfo(modelType, preload.Relation)
 		if relInfo == nil {
@@ -1128,7 +1135,75 @@ func (h *Handler) applyPreloads(model interface{}, query common.SelectQuery, pre
 		// For now, we'll preload without conditions
 		// TODO: Implement column selection and filtering for preloads
 		// This requires a more sophisticated approach with callbacks or query builders
-		query = query.Preload(relationFieldName)
+		// Apply preloading
+
+		logger.Debug("Applying preload: %s", relationFieldName)
+		query = query.PreloadRelation(relationFieldName, func(sq common.SelectQuery) common.SelectQuery {
+			if len(preload.OmitColumns) > 0 {
+				allCols := reflection.GetModelColumns(model)
+				// Remove omitted columns
+				preload.Columns = []string{}
+				for _, col := range allCols {
+					addCols := true
+					for _, omitCol := range preload.OmitColumns {
+						if col == omitCol {
+							addCols = false
+							break
+						}
+					}
+					if addCols {
+						preload.Columns = append(preload.Columns, col)
+					}
+				}
+			}
+
+			if len(preload.Columns) > 0 {
+				// Ensure foreign key is included in column selection for GORM to establish the relationship
+				columns := make([]string, len(preload.Columns))
+				copy(columns, preload.Columns)
+
+				// Add foreign key if not already present
+				if relInfo.foreignKey != "" {
+					// Convert struct field name (e.g., DepartmentID) to snake_case (e.g., department_id)
+					foreignKeyColumn := toSnakeCase(relInfo.foreignKey)
+
+					hasForeignKey := false
+					for _, col := range columns {
+						if col == foreignKeyColumn || col == relInfo.foreignKey {
+							hasForeignKey = true
+							break
+						}
+					}
+					if !hasForeignKey {
+						columns = append(columns, foreignKeyColumn)
+					}
+				}
+
+				sq = sq.Column(columns...)
+			}
+
+			if len(preload.Filters) > 0 {
+				for _, filter := range preload.Filters {
+					sq = h.applyFilter(sq, filter)
+				}
+			}
+			if len(preload.Sort) > 0 {
+				for _, sort := range preload.Sort {
+					sq = sq.Order(fmt.Sprintf("%s %s", sort.Column, sort.Direction))
+				}
+			}
+
+			if len(preload.Where) > 0 {
+				sq = sq.Where(preload.Where)
+			}
+
+			if preload.Limit != nil && *preload.Limit > 0 {
+				sq = sq.Limit(*preload.Limit)
+			}
+
+			return sq
+		})
+
 		logger.Debug("Applied Preload for relation: %s (field: %s)", preload.Relation, relationFieldName)
 	}
 
@@ -1186,3 +1261,28 @@ func (h *Handler) extractTagValue(tag, key string) string {
 	}
 	return ""
 }
+
+// toSnakeCase converts a PascalCase or camelCase string to snake_case
+func toSnakeCase(s string) string {
+	var result strings.Builder
+	runes := []rune(s)
+
+	for i := 0; i < len(runes); i++ {
+		r := runes[i]
+
+		if i > 0 && r >= 'A' && r <= 'Z' {
+			// Check if previous character is lowercase or if next character is lowercase
+			prevIsLower := runes[i-1] >= 'a' && runes[i-1] <= 'z'
+			nextIsLower := i+1 < len(runes) && runes[i+1] >= 'a' && runes[i+1] <= 'z'
+
+			// Add underscore if this is the start of a new word
+			// (previous was lowercase OR this is followed by lowercase)
+			if prevIsLower || nextIsLower {
+				result.WriteByte('_')
+			}
+		}
+
+		result.WriteRune(r)
+	}
+	return strings.ToLower(result.String())
+}

pkg/restheadspec/handler.go

@@ -7,6 +7,7 @@ import (
 	"net/http"
 	"reflect"
 	"runtime/debug"
+	"strconv"
 	"strings"
 
 	"github.com/bitechdev/ResolveSpec/pkg/common"
@@ -133,9 +134,15 @@ func (h *Handler) Handle(w common.ResponseWriter, r common.Request, params map[s
 			h.sendError(w, http.StatusBadRequest, "invalid_request", "Invalid request body", err)
 			return
 		}
-		h.handleCreate(ctx, w, data, options)
+		validId, _ := strconv.ParseInt(id, 10, 64)
+		if validId > 0 {
+			h.handleUpdate(ctx, w, id, nil, data, options)
+		} else {
+			h.handleCreate(ctx, w, data, options)
+		}
 	case "PUT", "PATCH":
 		// Update operation
+
 		body, err := r.Body()
 		if err != nil {
 			logger.Error("Failed to read request body: %v", err)
@@ -257,14 +264,28 @@ func (h *Handler) handleRead(ctx context.Context, w common.ResponseWriter, id st
 	if len(options.ComputedQL) > 0 {
 		for colName, colExpr := range options.ComputedQL {
 			logger.Debug("Applying computed column: %s", colName)
-			query = query.ColumnExpr("(?) AS "+colName, colExpr)
+			query = query.ColumnExpr(fmt.Sprintf("(%s) AS %s", colExpr, colName))
+			for colIndex := range options.Columns {
+				if options.Columns[colIndex] == colName {
+					// Remove the computed column from the selected columns to avoid duplication
+					options.Columns = append(options.Columns[:colIndex], options.Columns[colIndex+1:]...)
+					break
+				}
+			}
 		}
 	}
 
 	if len(options.ComputedColumns) > 0 {
 		for _, cu := range options.ComputedColumns {
 			logger.Debug("Applying computed column: %s", cu.Name)
-			query = query.ColumnExpr("(?) AS "+cu.Name, cu.Expression)
+			query = query.ColumnExpr(fmt.Sprintf("(%s) AS %s", cu.Expression, cu.Name))
+			for colIndex := range options.Columns {
+				if options.Columns[colIndex] == cu.Name {
+					// Remove the computed column from the selected columns to avoid duplication
+					options.Columns = append(options.Columns[:colIndex], options.Columns[colIndex+1:]...)
+					break
+				}
+			}
 		}
 	}
 
@@ -274,18 +295,95 @@ func (h *Handler) handleRead(ctx context.Context, w common.ResponseWriter, id st
 		query = query.Column(options.Columns...)
 	}
 
-	// Apply preloading
+	// Apply expand (Just expand to Preload for now)
-	for _, preload := range options.Preload {
-		logger.Debug("Applying preload: %s", preload.Relation)
-		query = query.Preload(preload.Relation)
-	}
-
-	// Apply expand (LEFT JOIN)
 	for _, expand := range options.Expand {
 		logger.Debug("Applying expand: %s", expand.Relation)
+		sorts := make([]common.SortOption, 0)
+		for _, s := range strings.Split(expand.Sort, ",") {
+			if s == "" {
+				continue
+			}
+			dir := "ASC"
+			if strings.HasPrefix(s, "-") || strings.HasSuffix(strings.ToUpper(s), " DESC") {
+				dir = "DESC"
+				s = strings.TrimPrefix(s, "-")
+				s = strings.TrimSuffix(strings.ToLower(s), " desc")
+			}
+			sorts = append(sorts, common.SortOption{
+				Column: s, Direction: dir,
+			})
+		}
 		// Note: Expand would require JOIN implementation
 		// For now, we'll use Preload as a fallback
-		query = query.Preload(expand.Relation)
+		// query = query.Preload(expand.Relation)
+		if options.Preload == nil {
+			options.Preload = make([]common.PreloadOption, 0)
+		}
+		skip := false
+		for idx := range options.Preload {
+			if options.Preload[idx].Relation == expand.Relation {
+				skip = true
+				continue
+			}
+		}
+		if !skip {
+			options.Preload = append(options.Preload, common.PreloadOption{
+				Relation: expand.Relation,
+				Columns:  expand.Columns,
+				Sort:     sorts,
+				Where:    expand.Where,
+			})
+		}
+	}
+
+	// Apply preloading
+	for idx := range options.Preload {
+		preload := options.Preload[idx]
+		logger.Debug("Applying preload: %s", preload.Relation)
+		query = query.PreloadRelation(preload.Relation, func(sq common.SelectQuery) common.SelectQuery {
+			if len(preload.OmitColumns) > 0 {
+				allCols := reflection.GetModelColumns(model)
+				// Remove omitted columns
+				preload.Columns = []string{}
+				for _, col := range allCols {
+					addCols := true
+					for _, omitCol := range preload.OmitColumns {
+						if col == omitCol {
+							addCols = false
+							break
+						}
+					}
+					if addCols {
+						preload.Columns = append(preload.Columns, col)
+					}
+				}
+			}
+
+			if len(preload.Columns) > 0 {
+				sq = sq.Column(preload.Columns...)
+			}
+
+			if len(preload.Filters) > 0 {
+				for _, filter := range preload.Filters {
+					sq = h.applyFilter(sq, filter, "", false, "AND")
+				}
+			}
+			if len(preload.Sort) > 0 {
+				for _, sort := range preload.Sort {
+					sq = sq.Order(fmt.Sprintf("%s %s", sort.Column, sort.Direction))
+				}
+			}
+
+			if len(preload.Where) > 0 {
+				sq = sq.Where(preload.Where)
+			}
+
+			if preload.Limit != nil && *preload.Limit > 0 {
+				sq = sq.Limit(*preload.Limit)
+			}
+
+			return sq
+		})
 	}
 
 	// Apply DISTINCT if requested
@@ -326,8 +424,10 @@ func (h *Handler) handleRead(ctx context.Context, w common.ResponseWriter, id st
 
 	// If ID is provided, filter by ID
 	if id != "" {
-		logger.Debug("Filtering by ID: %s", id)
+		pkName := reflection.GetPrimaryKeyName(model)
-		query = query.Where("id = ?", id)
+		logger.Debug("Filtering by ID=%s: %s", pkName, id)
+
+		query = query.Where(fmt.Sprintf("%s = ?", common.QuoteIdent(pkName)), id)
 	}
 
 	// Apply sorting
@@ -433,7 +533,7 @@ func (h *Handler) handleRead(ctx context.Context, w common.ResponseWriter, id st
 
 	metadata := &common.Metadata{
 		Total:    int64(total),
-		Count:    int64(common.Len(modelPtr)),
+		Count:    int64(reflection.Len(modelPtr)),
 		Filtered: int64(total),
 		Limit:    limit,
 		Offset:   offset,
@@ -484,22 +584,6 @@ func (h *Handler) handleCreate(ctx context.Context, w common.ResponseWriter, dat
 
 	logger.Info("Creating record in %s.%s", schema, entity)
 
-	// Check if data is a single map with nested relations
-	if dataMap, ok := data.(map[string]interface{}); ok {
-		if h.shouldUseNestedProcessor(dataMap, model) {
-			logger.Info("Using nested CUD processor for create operation")
-			result, err := h.nestedProcessor.ProcessNestedCUD(ctx, "insert", dataMap, model, make(map[string]interface{}), tableName)
-			if err != nil {
-				logger.Error("Error in nested create: %v", err)
-				h.sendError(w, http.StatusInternalServerError, "create_error", "Error creating record with nested data", err)
-				return
-			}
-			logger.Info("Successfully created record with nested data, ID: %v", result.ID)
-			h.sendResponse(w, result.Data, nil)
-			return
-		}
-	}
-
 	// Execute BeforeCreate hooks
 	hookCtx := &HookContext{
 		Context:   ctx,
@@ -522,172 +606,113 @@ func (h *Handler) handleCreate(ctx context.Context, w common.ResponseWriter, dat
 	// Use potentially modified data from hook context
 	data = hookCtx.Data
 
-	// Handle batch creation
+	// Normalize data to slice for unified processing
-	dataValue := reflect.ValueOf(data)
+	dataSlice := h.normalizeToSlice(data)
-	if dataValue.Kind() == reflect.Slice || dataValue.Kind() == reflect.Array {
+	logger.Debug("Processing %d item(s) for creation", len(dataSlice))
-		logger.Debug("Batch creation detected, count: %d", dataValue.Len())
 
-		// Check if any item needs nested processing
+	// Process all items in a transaction
-		hasNestedData := false
+	results := make([]interface{}, 0, len(dataSlice))
-		for i := 0; i < dataValue.Len(); i++ {
+	err := h.db.RunInTransaction(ctx, func(tx common.Database) error {
-			item := dataValue.Index(i).Interface()
+		// Create temporary nested processor with transaction
-			if itemMap, ok := item.(map[string]interface{}); ok {
+		txNestedProcessor := common.NewNestedCUDProcessor(tx, h.registry, h)
-				if h.shouldUseNestedProcessor(itemMap, model) {
-					hasNestedData = true
-					break
-				}
-			}
-		}
 
-		if hasNestedData {
+		for i, item := range dataSlice {
-			logger.Info("Using nested CUD processor for batch create with nested data")
+			itemMap, ok := item.(map[string]interface{})
-			results := make([]interface{}, 0, dataValue.Len())
+			if !ok {
-			err := h.db.RunInTransaction(ctx, func(tx common.Database) error {
+				// Convert to map if needed
-				// Temporarily swap the database to use transaction
-				originalDB := h.nestedProcessor
-				h.nestedProcessor = common.NewNestedCUDProcessor(tx, h.registry, h)
-				defer func() {
-					h.nestedProcessor = originalDB
-				}()
-
-				for i := 0; i < dataValue.Len(); i++ {
-					item := dataValue.Index(i).Interface()
-					if itemMap, ok := item.(map[string]interface{}); ok {
-						result, err := h.nestedProcessor.ProcessNestedCUD(ctx, "insert", itemMap, model, make(map[string]interface{}), tableName)
-						if err != nil {
-							return fmt.Errorf("failed to process item: %w", err)
-						}
-						results = append(results, result.Data)
-					}
-				}
-				return nil
-			})
-			if err != nil {
-				logger.Error("Error creating records with nested data: %v", err)
-				h.sendError(w, http.StatusInternalServerError, "create_error", "Error creating records with nested data", err)
-				return
-			}
-
-			// Execute AfterCreate hooks
-			hookCtx.Result = map[string]interface{}{"created": len(results), "data": results}
-			hookCtx.Error = nil
-
-			if err := h.hooks.Execute(AfterCreate, hookCtx); err != nil {
-				logger.Error("AfterCreate hook failed: %v", err)
-				h.sendError(w, http.StatusInternalServerError, "hook_error", "Hook execution failed", err)
-				return
-			}
-
-			logger.Info("Successfully created %d records with nested data", len(results))
-			h.sendResponse(w, results, nil)
-			return
-		}
-
-		// Standard batch insert without nested relations
-		// Use transaction for batch insert
-		err := h.db.RunInTransaction(ctx, func(tx common.Database) error {
-			for i := 0; i < dataValue.Len(); i++ {
-				item := dataValue.Index(i).Interface()
-
-				// Convert item to model type - create a pointer to the model
-				modelValue := reflect.New(reflect.TypeOf(model)).Interface()
 				jsonData, err := json.Marshal(item)
 				if err != nil {
-					return fmt.Errorf("failed to marshal item: %w", err)
+					return fmt.Errorf("failed to marshal item %d: %w", i, err)
 				}
-				if err := json.Unmarshal(jsonData, modelValue); err != nil {
+				itemMap = make(map[string]interface{})
-					return fmt.Errorf("failed to unmarshal item: %w", err)
+				if err := json.Unmarshal(jsonData, &itemMap); err != nil {
-				}
+					return fmt.Errorf("failed to unmarshal item %d: %w", i, err)
-
-				query := tx.NewInsert().Model(modelValue).Table(tableName)
-
-				// Execute BeforeScan hooks - pass query chain so hooks can modify it
-				batchHookCtx := &HookContext{
-					Context:   ctx,
-					Handler:   h,
-					Schema:    schema,
-					Entity:    entity,
-					TableName: tableName,
-					Model:     model,
-					Options:   options,
-					Data:      modelValue,
-					Writer:    w,
-					Query:     query,
-				}
-				if err := h.hooks.Execute(BeforeScan, batchHookCtx); err != nil {
-					return fmt.Errorf("BeforeScan hook failed: %w", err)
-				}
-
-				// Use potentially modified query from hook context
-				if modifiedQuery, ok := batchHookCtx.Query.(common.InsertQuery); ok {
-					query = modifiedQuery
-				}
-
-				if _, err := query.Exec(ctx); err != nil {
-					return fmt.Errorf("failed to insert record: %w", err)
 				}
 			}
-			return nil
-		})
 
-		if err != nil {
+			// Extract nested relations if present (but don't process them yet)
-			logger.Error("Error creating records: %v", err)
+			var nestedRelations map[string]interface{}
-			h.sendError(w, http.StatusInternalServerError, "create_error", "Error creating records", err)
+			if h.shouldUseNestedProcessor(itemMap, model) {
-			return
+				logger.Debug("Extracting nested relations for item %d", i)
+				cleanedData, relations, err := h.extractNestedRelations(itemMap, model)
+				if err != nil {
+					return fmt.Errorf("failed to extract nested relations for item %d: %w", i, err)
+				}
+				itemMap = cleanedData
+				nestedRelations = relations
+			}
+
+			// Convert item to model type - create a pointer to the model
+			modelValue := reflect.New(reflect.TypeOf(model)).Interface()
+			jsonData, err := json.Marshal(itemMap)
+			if err != nil {
+				return fmt.Errorf("failed to marshal item %d: %w", i, err)
+			}
+			if err := json.Unmarshal(jsonData, modelValue); err != nil {
+				return fmt.Errorf("failed to unmarshal item %d: %w", i, err)
+			}
+
+			// Create insert query
+			query := tx.NewInsert().Model(modelValue).Table(tableName).Returning("*")
+
+			// Execute BeforeScan hooks - pass query chain so hooks can modify it
+			itemHookCtx := &HookContext{
+				Context:   ctx,
+				Handler:   h,
+				Schema:    schema,
+				Entity:    entity,
+				TableName: tableName,
+				Model:     model,
+				Options:   options,
+				Data:      modelValue,
+				Writer:    w,
+				Query:     query,
+			}
+			if err := h.hooks.Execute(BeforeScan, itemHookCtx); err != nil {
+				return fmt.Errorf("BeforeScan hook failed for item %d: %w", i, err)
+			}
+
+			// Use potentially modified query from hook context
+			if modifiedQuery, ok := itemHookCtx.Query.(common.InsertQuery); ok {
+				query = modifiedQuery
+			}
+
+			// Execute insert and get the ID
+			if _, err := query.Exec(ctx); err != nil {
+				return fmt.Errorf("failed to insert item %d: %w", i, err)
+			}
+
+			// Get the inserted ID
+			insertedID := reflection.GetPrimaryKeyValue(modelValue)
+
+			// Now process nested relations with the parent ID
+			if len(nestedRelations) > 0 {
+				logger.Debug("Processing nested relations for item %d with parent ID: %v", i, insertedID)
+				if err := h.processChildRelationsWithParentID(ctx, txNestedProcessor, "insert", nestedRelations, model, insertedID); err != nil {
+					return fmt.Errorf("failed to process nested relations for item %d: %w", i, err)
+				}
+			}
+
+			results = append(results, modelValue)
 		}
+		return nil
+	})
 
-		// Execute AfterCreate hooks for batch creation
-		hookCtx.Result = map[string]interface{}{"created": dataValue.Len()}
-		hookCtx.Error = nil
-
-		if err := h.hooks.Execute(AfterCreate, hookCtx); err != nil {
-			logger.Error("AfterCreate hook failed: %v", err)
-			h.sendError(w, http.StatusInternalServerError, "hook_error", "Hook execution failed", err)
-			return
-		}
-
-		h.sendResponse(w, map[string]interface{}{"created": dataValue.Len()}, nil)
-		return
-	}
-
-	// Single record creation - create a pointer to the model
-	modelValue := reflect.New(reflect.TypeOf(model)).Interface()
-	jsonData, err := json.Marshal(data)
 	if err != nil {
-		logger.Error("Error marshaling data: %v", err)
+		logger.Error("Error creating records: %v", err)
-		h.sendError(w, http.StatusBadRequest, "invalid_data", "Invalid data format", err)
+		h.sendError(w, http.StatusInternalServerError, "create_error", "Error creating records", err)
-		return
-	}
-	if err := json.Unmarshal(jsonData, modelValue); err != nil {
-		logger.Error("Error unmarshaling data: %v", err)
-		h.sendError(w, http.StatusBadRequest, "invalid_data", "Invalid data format", err)
 		return
 	}
 
-	query := h.db.NewInsert().Model(modelValue).Table(tableName)
+	// Execute AfterCreate hooks
-
+	var responseData interface{}
-	// Execute BeforeScan hooks - pass query chain so hooks can modify it
+	if len(results) == 1 {
-	hookCtx.Data = modelValue
+		responseData = results[0]
-	hookCtx.Query = query
+		hookCtx.Result = results[0]
-	if err := h.hooks.Execute(BeforeScan, hookCtx); err != nil {
+	} else {
-		logger.Error("BeforeScan hook failed: %v", err)
+		responseData = results
-		h.sendError(w, http.StatusBadRequest, "hook_error", "Hook execution failed", err)
+		hookCtx.Result = map[string]interface{}{"created": len(results), "data": results}
-		return
 	}
-
-	// Use potentially modified query from hook context
-	if modifiedQuery, ok := hookCtx.Query.(common.InsertQuery); ok {
-		query = modifiedQuery
-	}
-
-	if _, err := query.Exec(ctx); err != nil {
-		logger.Error("Error creating record: %v", err)
-		h.sendError(w, http.StatusInternalServerError, "create_error", "Error creating record", err)
-		return
-	}
-
-	// Execute AfterCreate hooks for single record creation
-	hookCtx.Result = modelValue
 	hookCtx.Error = nil
 
 	if err := h.hooks.Execute(AfterCreate, hookCtx); err != nil {
@@ -696,7 +721,8 @@ func (h *Handler) handleCreate(ctx context.Context, w common.ResponseWriter, dat
 		return
 	}
 
-	h.sendResponse(w, modelValue, nil)
+	logger.Info("Successfully created %d record(s)", len(results))
+	h.sendResponseWithOptions(w, responseData, nil, &options)
 }
 
 func (h *Handler) handleUpdate(ctx context.Context, w common.ResponseWriter, id string, idPtr *int64, data interface{}, options ExtendedRequestOptions) {
@@ -714,46 +740,6 @@ func (h *Handler) handleUpdate(ctx context.Context, w common.ResponseWriter, id
 
 	logger.Info("Updating record in %s.%s", schema, entity)
 
-	// Convert data to map first for nested processor check
-	dataMap, ok := data.(map[string]interface{})
-	if !ok {
-		jsonData, err := json.Marshal(data)
-		if err != nil {
-			logger.Error("Error marshaling data: %v", err)
-			h.sendError(w, http.StatusBadRequest, "invalid_data", "Invalid data format", err)
-			return
-		}
-		if err := json.Unmarshal(jsonData, &dataMap); err != nil {
-			logger.Error("Error unmarshaling data: %v", err)
-			h.sendError(w, http.StatusBadRequest, "invalid_data", "Invalid data format", err)
-			return
-		}
-	}
-
-	// Check if we should use nested processing
-	if h.shouldUseNestedProcessor(dataMap, model) {
-		logger.Info("Using nested CUD processor for update operation")
-		// Ensure ID is in the data map
-		var targetID interface{}
-		if id != "" {
-			targetID = id
-		} else if idPtr != nil {
-			targetID = *idPtr
-		}
-		if targetID != nil {
-			dataMap["id"] = targetID
-		}
-		result, err := h.nestedProcessor.ProcessNestedCUD(ctx, "update", dataMap, model, make(map[string]interface{}), tableName)
-		if err != nil {
-			logger.Error("Error in nested update: %v", err)
-			h.sendError(w, http.StatusInternalServerError, "update_error", "Error updating record with nested data", err)
-			return
-		}
-		logger.Info("Successfully updated record with nested data, rows: %d", result.AffectedRows)
-		h.sendResponse(w, result.Data, nil)
-		return
-	}
-
 	// Execute BeforeUpdate hooks
 	hookCtx := &HookContext{
 		Context:   ctx,
@@ -777,8 +763,8 @@ func (h *Handler) handleUpdate(ctx context.Context, w common.ResponseWriter, id
 	// Use potentially modified data from hook context
 	data = hookCtx.Data
 
-	// Convert data to map (again if modified by hooks)
+	// Convert data to map
-	dataMap, ok = data.(map[string]interface{})
+	dataMap, ok := data.(map[string]interface{})
 	if !ok {
 		jsonData, err := json.Marshal(data)
 		if err != nil {
@@ -793,33 +779,74 @@ func (h *Handler) handleUpdate(ctx context.Context, w common.ResponseWriter, id
 		}
 	}
 
-	query := h.db.NewUpdate().Table(tableName).SetMap(dataMap)
+	// Determine target ID
-
+	var targetID interface{}
-	// Apply ID filter
+	if id != "" {
-	switch {
+		targetID = id
-	case id != "":
+	} else if idPtr != nil {
-		query = query.Where("id = ?", id)
+		targetID = *idPtr
-	case idPtr != nil:
+	} else {
-		query = query.Where("id = ?", *idPtr)
-	default:
 		h.sendError(w, http.StatusBadRequest, "missing_id", "ID is required for update", nil)
 		return
 	}
 
-	// Execute BeforeScan hooks - pass query chain so hooks can modify it
+	// Process nested relations if present
-	hookCtx.Query = query
+	err := h.db.RunInTransaction(ctx, func(tx common.Database) error {
-	if err := h.hooks.Execute(BeforeScan, hookCtx); err != nil {
+		// Create temporary nested processor with transaction
-		logger.Error("BeforeScan hook failed: %v", err)
+		txNestedProcessor := common.NewNestedCUDProcessor(tx, h.registry, h)
-		h.sendError(w, http.StatusBadRequest, "hook_error", "Hook execution failed", err)
-		return
-	}
 
-	// Use potentially modified query from hook context
+		// Extract nested relations if present (but don't process them yet)
-	if modifiedQuery, ok := hookCtx.Query.(common.UpdateQuery); ok {
+		var nestedRelations map[string]interface{}
-		query = modifiedQuery
+		if h.shouldUseNestedProcessor(dataMap, model) {
-	}
+			logger.Debug("Extracting nested relations for update")
+			cleanedData, relations, err := h.extractNestedRelations(dataMap, model)
+			if err != nil {
+				return fmt.Errorf("failed to extract nested relations: %w", err)
+			}
+			dataMap = cleanedData
+			nestedRelations = relations
+		}
+
+		// Ensure ID is in the data map for the update
+		dataMap["id"] = targetID
+
+		// Create update query
+		query := tx.NewUpdate().Model(model).Table(tableName).SetMap(dataMap)
+		pkName := reflection.GetPrimaryKeyName(model)
+		query = query.Where(fmt.Sprintf("%s = ?", common.QuoteIdent(pkName)), targetID)
+
+		// Execute BeforeScan hooks - pass query chain so hooks can modify it
+		hookCtx.Query = query
+		if err := h.hooks.Execute(BeforeScan, hookCtx); err != nil {
+			return fmt.Errorf("BeforeScan hook failed: %w", err)
+		}
+
+		// Use potentially modified query from hook context
+		if modifiedQuery, ok := hookCtx.Query.(common.UpdateQuery); ok {
+			query = modifiedQuery
+		}
+
+		// Execute update
+		result, err := query.Exec(ctx)
+		if err != nil {
+			return fmt.Errorf("failed to update record: %w", err)
+		}
+
+		// Now process nested relations with the parent ID
+		if len(nestedRelations) > 0 {
+			logger.Debug("Processing nested relations for update with parent ID: %v", targetID)
+			if err := h.processChildRelationsWithParentID(ctx, txNestedProcessor, "update", nestedRelations, model, targetID); err != nil {
+				return fmt.Errorf("failed to process nested relations: %w", err)
+			}
+		}
+
+		// Store result for hooks
+		hookCtx.Result = map[string]interface{}{
+			"updated": result.RowsAffected(),
+		}
+		return nil
+	})
 
-	result, err := query.Exec(ctx)
 	if err != nil {
 		logger.Error("Error updating record: %v", err)
 		h.sendError(w, http.StatusInternalServerError, "update_error", "Error updating record", err)
@@ -827,19 +854,15 @@ func (h *Handler) handleUpdate(ctx context.Context, w common.ResponseWriter, id
 	}
 
 	// Execute AfterUpdate hooks
-	responseData := map[string]interface{}{
-		"updated": result.RowsAffected(),
-	}
-	hookCtx.Result = responseData
 	hookCtx.Error = nil
-
 	if err := h.hooks.Execute(AfterUpdate, hookCtx); err != nil {
 		logger.Error("AfterUpdate hook failed: %v", err)
 		h.sendError(w, http.StatusInternalServerError, "hook_error", "Hook execution failed", err)
 		return
 	}
 
-	h.sendResponse(w, responseData, nil)
+	logger.Info("Successfully updated record with ID: %v", targetID)
+	h.sendResponseWithOptions(w, hookCtx.Result, nil, &options)
 }
 
 func (h *Handler) handleDelete(ctx context.Context, w common.ResponseWriter, id string, data interface{}) {
@@ -883,7 +906,7 @@ func (h *Handler) handleDelete(ctx context.Context, w common.ResponseWriter, id
 						continue
 					}
 
-					query := tx.NewDelete().Table(tableName).Where("id = ?", itemID)
+					query := tx.NewDelete().Table(tableName).Where(fmt.Sprintf("%s = ?", common.QuoteIdent(reflection.GetPrimaryKeyName(model))), itemID)
 
 					result, err := query.Exec(ctx)
 					if err != nil {
@@ -950,7 +973,7 @@ func (h *Handler) handleDelete(ctx context.Context, w common.ResponseWriter, id
 						continue
 					}
 
-					query := tx.NewDelete().Table(tableName).Where("id = ?", itemID)
+					query := tx.NewDelete().Table(tableName).Where(fmt.Sprintf("%s = ?", common.QuoteIdent(reflection.GetPrimaryKeyName(model))), itemID)
 					result, err := query.Exec(ctx)
 					if err != nil {
 						return fmt.Errorf("failed to delete record %v: %w", itemID, err)
@@ -1001,7 +1024,7 @@ func (h *Handler) handleDelete(ctx context.Context, w common.ResponseWriter, id
 							continue
 						}
 
-						query := tx.NewDelete().Table(tableName).Where("id = ?", itemID)
+						query := tx.NewDelete().Table(tableName).Where(fmt.Sprintf("%s = ?", common.QuoteIdent(reflection.GetPrimaryKeyName(model))), itemID)
 						result, err := query.Exec(ctx)
 						if err != nil {
 							return fmt.Errorf("failed to delete record %v: %w", itemID, err)
@@ -1061,7 +1084,7 @@ func (h *Handler) handleDelete(ctx context.Context, w common.ResponseWriter, id
 		return
 	}
 
-	query = query.Where("id = ?", id)
+	query = query.Where(fmt.Sprintf("%s = ?", common.QuoteIdent(reflection.GetPrimaryKeyName(model))), id)
 
 	// Execute BeforeScan hooks - pass query chain so hooks can modify it
 	hookCtx.Query = query
@@ -1099,6 +1122,196 @@ func (h *Handler) handleDelete(ctx context.Context, w common.ResponseWriter, id
 	h.sendResponse(w, responseData, nil)
 }
 
+// normalizeToSlice converts data to a slice. Single items become a 1-item slice.
+func (h *Handler) normalizeToSlice(data interface{}) []interface{} {
+	if data == nil {
+		return []interface{}{}
+	}
+
+	dataValue := reflect.ValueOf(data)
+	if dataValue.Kind() == reflect.Slice || dataValue.Kind() == reflect.Array {
+		result := make([]interface{}, dataValue.Len())
+		for i := 0; i < dataValue.Len(); i++ {
+			result[i] = dataValue.Index(i).Interface()
+		}
+		return result
+	}
+
+	// Single item - return as 1-item slice
+	return []interface{}{data}
+}
+
+// extractNestedRelations extracts nested relations from data, returning cleaned data and relations
+// This does NOT process the relations, just separates them for later processing
+func (h *Handler) extractNestedRelations(
+	data map[string]interface{},
+	model interface{},
+) (map[string]interface{}, map[string]interface{}, error) {
+	// Get model type for reflection
+	modelType := reflect.TypeOf(model)
+	for modelType != nil && (modelType.Kind() == reflect.Ptr || modelType.Kind() == reflect.Slice || modelType.Kind() == reflect.Array) {
+		modelType = modelType.Elem()
+	}
+
+	if modelType == nil || modelType.Kind() != reflect.Struct {
+		return data, nil, fmt.Errorf("model must be a struct type, got %v", modelType)
+	}
+
+	// Separate relation fields from regular fields
+	cleanedData := make(map[string]interface{})
+	relations := make(map[string]interface{})
+
+	for key, value := range data {
+		// Skip _request field
+		if key == "_request" {
+			continue
+		}
+
+		// Check if this field is a relation
+		relInfo := h.GetRelationshipInfo(modelType, key)
+		if relInfo != nil {
+			logger.Debug("Found nested relation field: %s (type: %s)", key, relInfo.RelationType)
+			relations[key] = value
+		} else {
+			cleanedData[key] = value
+		}
+	}
+
+	return cleanedData, relations, nil
+}
+
+// processChildRelationsWithParentID processes nested relations with a parent ID
+func (h *Handler) processChildRelationsWithParentID(
+	ctx context.Context,
+	processor *common.NestedCUDProcessor,
+	operation string,
+	relations map[string]interface{},
+	parentModel interface{},
+	parentID interface{},
+) error {
+	// Get model type for reflection
+	modelType := reflect.TypeOf(parentModel)
+	for modelType != nil && (modelType.Kind() == reflect.Ptr || modelType.Kind() == reflect.Slice || modelType.Kind() == reflect.Array) {
+		modelType = modelType.Elem()
+	}
+
+	if modelType == nil || modelType.Kind() != reflect.Struct {
+		return fmt.Errorf("model must be a struct type, got %v", modelType)
+	}
+
+	// Process each relation
+	for relationName, relationValue := range relations {
+		if relationValue == nil {
+			continue
+		}
+
+		// Get relationship info
+		relInfo := h.GetRelationshipInfo(modelType, relationName)
+		if relInfo == nil {
+			logger.Warn("No relationship info found for %s, skipping", relationName)
+			continue
+		}
+
+		// Process this relation with parent ID
+		if err := h.processChildRelationsForField(ctx, processor, operation, relationName, relationValue, relInfo, modelType, parentID); err != nil {
+			return fmt.Errorf("failed to process relation %s: %w", relationName, err)
+		}
+	}
+
+	return nil
+}
+
+// processChildRelationsForField processes a single nested relation field
+func (h *Handler) processChildRelationsForField(
+	ctx context.Context,
+	processor *common.NestedCUDProcessor,
+	operation string,
+	relationName string,
+	relationValue interface{},
+	relInfo *common.RelationshipInfo,
+	parentModelType reflect.Type,
+	parentID interface{},
+) error {
+	if relationValue == nil {
+		return nil
+	}
+
+	// Get the related model
+	field, found := parentModelType.FieldByName(relInfo.FieldName)
+	if !found {
+		return fmt.Errorf("field %s not found in model", relInfo.FieldName)
+	}
+
+	// Get the model type for the relation
+	relatedModelType := field.Type
+	if relatedModelType.Kind() == reflect.Slice {
+		relatedModelType = relatedModelType.Elem()
+	}
+	if relatedModelType.Kind() == reflect.Ptr {
+		relatedModelType = relatedModelType.Elem()
+	}
+
+	// Create an instance of the related model
+	relatedModel := reflect.New(relatedModelType).Elem().Interface()
+
+	// Get table name for related model
+	relatedTableName := h.getTableNameForRelatedModel(relatedModel, relInfo.JSONName)
+
+	// Prepare parent IDs for foreign key injection
+	parentIDs := make(map[string]interface{})
+	if relInfo.ForeignKey != "" && parentID != nil {
+		baseName := strings.TrimSuffix(relInfo.ForeignKey, "ID")
+		baseName = strings.TrimSuffix(strings.ToLower(baseName), "_id")
+		parentIDs[baseName] = parentID
+	}
+
+	// Process based on relation type and data structure
+	switch v := relationValue.(type) {
+	case map[string]interface{}:
+		// Single related object
+		_, err := processor.ProcessNestedCUD(ctx, operation, v, relatedModel, parentIDs, relatedTableName)
+		if err != nil {
+			return fmt.Errorf("failed to process single relation: %w", err)
+		}
+
+	case []interface{}:
+		// Multiple related objects
+		for i, item := range v {
+			if itemMap, ok := item.(map[string]interface{}); ok {
+				_, err := processor.ProcessNestedCUD(ctx, operation, itemMap, relatedModel, parentIDs, relatedTableName)
+				if err != nil {
+					return fmt.Errorf("failed to process relation item %d: %w", i, err)
+				}
+			}
+		}
+
+	case []map[string]interface{}:
+		// Multiple related objects (typed slice)
+		for i, itemMap := range v {
+			_, err := processor.ProcessNestedCUD(ctx, operation, itemMap, relatedModel, parentIDs, relatedTableName)
+			if err != nil {
+				return fmt.Errorf("failed to process relation item %d: %w", i, err)
+			}
+		}
+
+	default:
+		return fmt.Errorf("unsupported relation data type: %T", relationValue)
+	}
+
+	return nil
+}
+
+// getTableNameForRelatedModel gets the table name for a related model
+func (h *Handler) getTableNameForRelatedModel(model interface{}, defaultName string) string {
+	if provider, ok := model.(common.TableNameProvider); ok {
+		tableName := provider.TableName()
+		if tableName != "" {
+			return tableName
+		}
+	}
+	return defaultName
+}
+
 // qualifyColumnName ensures column name is fully qualified with table name if not already
 func (h *Handler) qualifyColumnName(columnName, fullTableName string) string {
 	// Check if column already has a table/schema prefix (contains a dot)
@@ -1341,6 +1554,16 @@ func (h *Handler) isNullable(field reflect.StructField) bool {
 }
 
 func (h *Handler) sendResponse(w common.ResponseWriter, data interface{}, metadata *common.Metadata) {
+	h.sendResponseWithOptions(w, data, metadata, nil)
+}
+
+// sendResponseWithOptions sends a response with optional formatting
+func (h *Handler) sendResponseWithOptions(w common.ResponseWriter, data interface{}, metadata *common.Metadata, options *ExtendedRequestOptions) {
+	// Normalize single-record arrays to objects if requested
+	if options != nil && options.SingleRecordAsObject {
+		data = h.normalizeResultArray(data)
+	}
+
 	response := common.Response{
 		Success:  true,
 		Data:     data,
@@ -1352,8 +1575,35 @@ func (h *Handler) sendResponse(w common.ResponseWriter, data interface{}, metada
 	}
 }
 
+// normalizeResultArray converts a single-element array to an object if requested
+// Returns the single element if data is a slice/array with exactly one element, otherwise returns data unchanged
+func (h *Handler) normalizeResultArray(data interface{}) interface{} {
+	if data == nil {
+		return data
+	}
+
+	// Use reflection to check if data is a slice or array
+	dataValue := reflect.ValueOf(data)
+	if dataValue.Kind() == reflect.Ptr {
+		dataValue = dataValue.Elem()
+	}
+
+	// Check if it's a slice or array with exactly one element
+	if (dataValue.Kind() == reflect.Slice || dataValue.Kind() == reflect.Array) && dataValue.Len() == 1 {
+		// Return the single element
+		return dataValue.Index(0).Interface()
+	}
+
+	return data
+}
+
 // sendFormattedResponse sends response with formatting options
 func (h *Handler) sendFormattedResponse(w common.ResponseWriter, data interface{}, metadata *common.Metadata, options ExtendedRequestOptions) {
+	// Normalize single-record arrays to objects if requested
+	if options.SingleRecordAsObject {
+		data = h.normalizeResultArray(data)
+	}
+
 	// Clean JSON if requested (remove null/empty fields)
 	if options.CleanJSON {
 		data = h.cleanJSON(data)
@@ -1441,6 +1691,9 @@ func (h *Handler) FetchRowNumber(ctx context.Context, tableName string, pkName s
 	if len(options.Sort) > 0 {
 		sortParts := make([]string, 0, len(options.Sort))
 		for _, sort := range options.Sort {
+			if sort.Column == "" {
+				continue
+			}
 			direction := "ASC"
 			if strings.EqualFold(sort.Direction, "desc") {
 				direction = "DESC"
@@ -1651,7 +1904,8 @@ func filterExtendedOptions(validator *common.ColumnValidator, options ExtendedRe
 }
 
 // shouldUseNestedProcessor determines if we should use nested CUD processing
-// It checks if the data contains nested relations or a _request field
+// It recursively checks if the data contains deeply nested relations or _request fields
+// Simple one-level relations without further nesting don't require the nested processor
 func (h *Handler) shouldUseNestedProcessor(data map[string]interface{}, model interface{}) bool {
 	return common.ShouldUseNestedProcessor(data, model, h)
 }
@@ -1713,12 +1967,40 @@ func (h *Handler) getRelationshipInfo(modelType reflect.Type, relationName strin
 				// Determine if it's belongsTo or hasMany/hasOne
 				if field.Type.Kind() == reflect.Slice {
 					info.relationType = "hasMany"
+					// Get the element type for slice
+					elemType := field.Type.Elem()
+					if elemType.Kind() == reflect.Ptr {
+						elemType = elemType.Elem()
+					}
+					if elemType.Kind() == reflect.Struct {
+						info.relatedModel = reflect.New(elemType).Elem().Interface()
+					}
 				} else if field.Type.Kind() == reflect.Ptr || field.Type.Kind() == reflect.Struct {
 					info.relationType = "belongsTo"
+					elemType := field.Type
+					if elemType.Kind() == reflect.Ptr {
+						elemType = elemType.Elem()
+					}
+					if elemType.Kind() == reflect.Struct {
+						info.relatedModel = reflect.New(elemType).Elem().Interface()
+					}
 				}
 			} else if strings.Contains(gormTag, "many2many") {
 				info.relationType = "many2many"
 				info.joinTable = h.extractTagValue(gormTag, "many2many")
+				// Get the element type for many2many (always slice)
+				if field.Type.Kind() == reflect.Slice {
+					elemType := field.Type.Elem()
+					if elemType.Kind() == reflect.Ptr {
+						elemType = elemType.Elem()
+					}
+					if elemType.Kind() == reflect.Struct {
+						info.relatedModel = reflect.New(elemType).Elem().Interface()
+					}
+				}
+			} else {
+				// Field has no GORM relationship tags, so it's not a relation
+				return nil
 			}
 
 			return info

pkg/restheadspec/handler_nested_test.go

@@ -0,0 +1,423 @@
+package restheadspec
+
+import (
+	"fmt"
+	"reflect"
+	"testing"
+)
+
+// Test models for nested CRUD operations
+type TestUser struct {
+	ID    int64      `json:"id" bun:"id,pk,autoincrement"`
+	Name  string     `json:"name"`
+	Posts []TestPost `json:"posts" gorm:"foreignKey:UserID"`
+}
+
+type TestPost struct {
+	ID       int64         `json:"id" bun:"id,pk,autoincrement"`
+	UserID   int64         `json:"user_id"`
+	Title    string        `json:"title"`
+	Comments []TestComment `json:"comments" gorm:"foreignKey:PostID"`
+}
+
+type TestComment struct {
+	ID      int64  `json:"id" bun:"id,pk,autoincrement"`
+	PostID  int64  `json:"post_id"`
+	Content string `json:"content"`
+}
+
+func (TestUser) TableName() string    { return "users" }
+func (TestPost) TableName() string    { return "posts" }
+func (TestComment) TableName() string { return "comments" }
+
+// Test extractNestedRelations function
+func TestExtractNestedRelations(t *testing.T) {
+	// Create handler
+	registry := &mockRegistry{
+		models: map[string]interface{}{
+			"users":    TestUser{},
+			"posts":    TestPost{},
+			"comments": TestComment{},
+		},
+	}
+	handler := NewHandler(nil, registry)
+
+	tests := []struct {
+		name               string
+		data               map[string]interface{}
+		model              interface{}
+		expectedCleanCount int
+		expectedRelCount   int
+	}{
+		{
+			name: "User with posts",
+			data: map[string]interface{}{
+				"name": "John Doe",
+				"posts": []map[string]interface{}{
+					{"title": "Post 1"},
+				},
+			},
+			model:              TestUser{},
+			expectedCleanCount: 1, // name
+			expectedRelCount:   1, // posts
+		},
+		{
+			name: "Post with comments",
+			data: map[string]interface{}{
+				"title": "Test Post",
+				"comments": []map[string]interface{}{
+					{"content": "Comment 1"},
+					{"content": "Comment 2"},
+				},
+			},
+			model:              TestPost{},
+			expectedCleanCount: 1, // title
+			expectedRelCount:   1, // comments
+		},
+		{
+			name: "User with nested posts and comments",
+			data: map[string]interface{}{
+				"name": "Jane Doe",
+				"posts": []map[string]interface{}{
+					{
+						"title": "Post 1",
+						"comments": []map[string]interface{}{
+							{"content": "Comment 1"},
+						},
+					},
+				},
+			},
+			model:              TestUser{},
+			expectedCleanCount: 1, // name
+			expectedRelCount:   1, // posts (which contains nested comments)
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			cleanedData, relations, err := handler.extractNestedRelations(tt.data, tt.model)
+			if err != nil {
+				t.Errorf("extractNestedRelations() error = %v", err)
+				return
+			}
+
+			if len(cleanedData) != tt.expectedCleanCount {
+				t.Errorf("Expected %d cleaned fields, got %d: %+v", tt.expectedCleanCount, len(cleanedData), cleanedData)
+			}
+
+			if len(relations) != tt.expectedRelCount {
+				t.Errorf("Expected %d relation fields, got %d: %+v", tt.expectedRelCount, len(relations), relations)
+			}
+
+			t.Logf("Cleaned data: %+v", cleanedData)
+			t.Logf("Relations: %+v", relations)
+		})
+	}
+}
+
+// Test shouldUseNestedProcessor function
+func TestShouldUseNestedProcessor(t *testing.T) {
+	registry := &mockRegistry{
+		models: map[string]interface{}{
+			"users": TestUser{},
+			"posts": TestPost{},
+		},
+	}
+	handler := NewHandler(nil, registry)
+
+	tests := []struct {
+		name     string
+		data     map[string]interface{}
+		model    interface{}
+		expected bool
+	}{
+		{
+			name: "Data with simple nested posts (no further nesting)",
+			data: map[string]interface{}{
+				"name": "John",
+				"posts": []map[string]interface{}{
+					{"title": "Post 1"},
+				},
+			},
+			model:    TestUser{},
+			expected: false, // Simple one-level nesting doesn't require nested processor
+		},
+		{
+			name: "Data with deeply nested relations",
+			data: map[string]interface{}{
+				"name": "John",
+				"posts": []map[string]interface{}{
+					{
+						"title": "Post 1",
+						"comments": []map[string]interface{}{
+							{"content": "Comment 1"},
+						},
+					},
+				},
+			},
+			model:    TestUser{},
+			expected: true, // Multi-level nesting requires nested processor
+		},
+		{
+			name: "Data without nested relations",
+			data: map[string]interface{}{
+				"name": "John",
+			},
+			model:    TestUser{},
+			expected: false,
+		},
+		{
+			name: "Data with _request field",
+			data: map[string]interface{}{
+				"_request": "insert",
+				"name":     "John",
+			},
+			model:    TestUser{},
+			expected: true,
+		},
+		{
+			name: "Nested data with _request field",
+			data: map[string]interface{}{
+				"name": "John",
+				"posts": []map[string]interface{}{
+					{
+						"_request": "insert",
+						"title":    "Post 1",
+					},
+				},
+			},
+			model:    TestUser{},
+			expected: true, // _request at nested level requires nested processor
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := handler.shouldUseNestedProcessor(tt.data, tt.model)
+			if result != tt.expected {
+				t.Errorf("shouldUseNestedProcessor() = %v, expected %v", result, tt.expected)
+			}
+		})
+	}
+}
+
+// Test normalizeToSlice function
+func TestNormalizeToSlice(t *testing.T) {
+	registry := &mockRegistry{}
+	handler := NewHandler(nil, registry)
+
+	tests := []struct {
+		name     string
+		input    interface{}
+		expected int // expected slice length
+	}{
+		{
+			name:     "Single object",
+			input:    map[string]interface{}{"name": "John"},
+			expected: 1,
+		},
+		{
+			name: "Slice of objects",
+			input: []map[string]interface{}{
+				{"name": "John"},
+				{"name": "Jane"},
+			},
+			expected: 2,
+		},
+		{
+			name: "Array of interfaces",
+			input: []interface{}{
+				map[string]interface{}{"name": "John"},
+				map[string]interface{}{"name": "Jane"},
+				map[string]interface{}{"name": "Bob"},
+			},
+			expected: 3,
+		},
+		{
+			name:     "Nil input",
+			input:    nil,
+			expected: 0,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := handler.normalizeToSlice(tt.input)
+			if len(result) != tt.expected {
+				t.Errorf("normalizeToSlice() returned slice of length %d, expected %d", len(result), tt.expected)
+			}
+		})
+	}
+}
+
+// Test GetRelationshipInfo function
+func TestGetRelationshipInfo(t *testing.T) {
+	registry := &mockRegistry{}
+	handler := NewHandler(nil, registry)
+
+	tests := []struct {
+		name         string
+		modelType    reflect.Type
+		relationName string
+		expectNil    bool
+	}{
+		{
+			name:         "User posts relation",
+			modelType:    reflect.TypeOf(TestUser{}),
+			relationName: "posts",
+			expectNil:    false,
+		},
+		{
+			name:         "Post comments relation",
+			modelType:    reflect.TypeOf(TestPost{}),
+			relationName: "comments",
+			expectNil:    false,
+		},
+		{
+			name:         "Non-existent relation",
+			modelType:    reflect.TypeOf(TestUser{}),
+			relationName: "nonexistent",
+			expectNil:    true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := handler.GetRelationshipInfo(tt.modelType, tt.relationName)
+			if tt.expectNil && result != nil {
+				t.Errorf("Expected nil, got %+v", result)
+			}
+			if !tt.expectNil && result == nil {
+				t.Errorf("Expected non-nil relationship info")
+			}
+			if result != nil {
+				t.Logf("Relationship info: FieldName=%s, JSONName=%s, RelationType=%s, ForeignKey=%s",
+					result.FieldName, result.JSONName, result.RelationType, result.ForeignKey)
+			}
+		})
+	}
+}
+
+// Mock registry for testing
+type mockRegistry struct {
+	models map[string]interface{}
+}
+
+func (m *mockRegistry) Register(name string, model interface{}) {
+	m.RegisterModel(name, model)
+}
+
+func (m *mockRegistry) RegisterModel(name string, model interface{}) error {
+	if m.models == nil {
+		m.models = make(map[string]interface{})
+	}
+	m.models[name] = model
+	return nil
+}
+
+func (m *mockRegistry) GetModelByEntity(schema, entity string) (interface{}, error) {
+	if model, ok := m.models[entity]; ok {
+		return model, nil
+	}
+	return nil, fmt.Errorf("model not found: %s", entity)
+}
+
+func (m *mockRegistry) GetModelByName(name string) (interface{}, error) {
+	if model, ok := m.models[name]; ok {
+		return model, nil
+	}
+	return nil, fmt.Errorf("model not found: %s", name)
+}
+
+func (m *mockRegistry) GetModel(name string) (interface{}, error) {
+	return m.GetModelByName(name)
+}
+
+func (m *mockRegistry) HasModel(schema, entity string) bool {
+	_, ok := m.models[entity]
+	return ok
+}
+
+func (m *mockRegistry) ListModels() []string {
+	models := make([]string, 0, len(m.models))
+	for name := range m.models {
+		models = append(models, name)
+	}
+	return models
+}
+
+func (m *mockRegistry) GetAllModels() map[string]interface{} {
+	return m.models
+}
+
+// TestMultiLevelRelationExtraction tests extracting deeply nested relations
+func TestMultiLevelRelationExtraction(t *testing.T) {
+	registry := &mockRegistry{
+		models: map[string]interface{}{
+			"users":    TestUser{},
+			"posts":    TestPost{},
+			"comments": TestComment{},
+		},
+	}
+	handler := NewHandler(nil, registry)
+
+	// Test data with 3 levels: User -> Posts -> Comments
+	testData := map[string]interface{}{
+		"name": "John Doe",
+		"posts": []map[string]interface{}{
+			{
+				"title": "First Post",
+				"comments": []map[string]interface{}{
+					{"content": "Great post!"},
+					{"content": "Thanks for sharing!"},
+				},
+			},
+			{
+				"title": "Second Post",
+				"comments": []map[string]interface{}{
+					{"content": "Interesting read"},
+				},
+			},
+		},
+	}
+
+	// Extract relations from user
+	cleanedData, relations, err := handler.extractNestedRelations(testData, TestUser{})
+	if err != nil {
+		t.Fatalf("Failed to extract relations: %v", err)
+	}
+
+	// Verify user data is cleaned
+	if len(cleanedData) != 1 || cleanedData["name"] != "John Doe" {
+		t.Errorf("Expected cleaned data to contain only name, got: %+v", cleanedData)
+	}
+
+	// Verify posts relation was extracted
+	if len(relations) != 1 {
+		t.Errorf("Expected 1 relation (posts), got %d", len(relations))
+	}
+
+	posts, ok := relations["posts"]
+	if !ok {
+		t.Fatal("Expected posts relation to be extracted")
+	}
+
+	// Verify posts is a slice with 2 items
+	postsSlice, ok := posts.([]map[string]interface{})
+	if !ok {
+		t.Fatalf("Expected posts to be []map[string]interface{}, got %T", posts)
+	}
+
+	if len(postsSlice) != 2 {
+		t.Errorf("Expected 2 posts, got %d", len(postsSlice))
+	}
+
+	// Verify first post has comments
+	if _, hasComments := postsSlice[0]["comments"]; !hasComments {
+		t.Error("Expected first post to have comments")
+	}
+
+	t.Logf("Successfully extracted multi-level nested relations")
+	t.Logf("Cleaned data: %+v", cleanedData)
+	t.Logf("Relations: %d posts with nested comments", len(postsSlice))
+}

pkg/restheadspec/headers.go

@@ -37,6 +37,9 @@ type ExtendedRequestOptions struct {
 	// Response format
 	ResponseFormat string // "simple", "detail", "syncfusion"
 
+	// Single record normalization - convert single-element arrays to objects
+	SingleRecordAsObject bool
+
 	// Transaction
 	AtomicTransaction bool
 }
@@ -99,10 +102,11 @@ func (h *Handler) parseOptionsFromHeaders(r common.Request) ExtendedRequestOptio
 			Sort:    make([]common.SortOption, 0),
 			Preload: make([]common.PreloadOption, 0),
 		},
-		AdvancedSQL:    make(map[string]string),
+		AdvancedSQL:          make(map[string]string),
-		ComputedQL:     make(map[string]string),
+		ComputedQL:           make(map[string]string),
-		Expand:         make([]ExpandOption, 0),
+		Expand:               make([]ExpandOption, 0),
-		ResponseFormat: "simple", // Default response format
+		ResponseFormat:       "simple",           // Default response format
+		SingleRecordAsObject: true,               // Default: normalize single-element arrays to objects
 	}
 
 	// Get all headers
@@ -146,7 +150,12 @@ func (h *Handler) parseOptionsFromHeaders(r common.Request) ExtendedRequestOptio
 
 		// Joins & Relations
 		case strings.HasPrefix(normalizedKey, "x-preload"):
-			h.parsePreload(&options, decodedValue)
+			if strings.HasSuffix(normalizedKey, "-where") {
+				continue
+			}
+			whereClaude := headers[fmt.Sprintf("%s-where", key)]
+			h.parsePreload(&options, decodedValue, decodeHeaderValue(whereClaude))
+
 		case strings.HasPrefix(normalizedKey, "x-expand"):
 			h.parseExpand(&options, decodedValue)
 		case strings.HasPrefix(normalizedKey, "x-custom-sql-join"):
@@ -194,6 +203,13 @@ func (h *Handler) parseOptionsFromHeaders(r common.Request) ExtendedRequestOptio
 			options.ResponseFormat = "detail"
 		case strings.HasPrefix(normalizedKey, "x-syncfusion"):
 			options.ResponseFormat = "syncfusion"
+		case strings.HasPrefix(normalizedKey, "x-single-record-as-object"):
+			// Parse as boolean - "false" disables, "true" enables (default is true)
+			if strings.EqualFold(decodedValue, "false") {
+				options.SingleRecordAsObject = false
+			} else if strings.EqualFold(decodedValue, "true") {
+				options.SingleRecordAsObject = true
+			}
 
 		// Transaction Control
 		case strings.HasPrefix(normalizedKey, "x-transaction-atomic"):
@@ -341,7 +357,15 @@ func (h *Handler) mapSearchOperator(colName, operator, value string) common.Filt
 
 // parsePreload parses x-preload header
 // Format: RelationName:field1,field2 or RelationName or multiple separated by |
-func (h *Handler) parsePreload(options *ExtendedRequestOptions, value string) {
+func (h *Handler) parsePreload(options *ExtendedRequestOptions, values ...string) {
+	if len(values) == 0 {
+		return
+	}
+	value := values[0]
+	whereClause := ""
+	if len(values) > 1 {
+		whereClause = values[1]
+	}
 	if value == "" {
 		return
 	}
@@ -358,6 +382,7 @@ func (h *Handler) parsePreload(options *ExtendedRequestOptions, value string) {
 		parts := strings.SplitN(preloadStr, ":", 2)
 		preload := common.PreloadOption{
 			Relation: strings.TrimSpace(parts[0]),
+			Where:    whereClause,
 		}
 
 		if len(parts) == 2 {

pkg/restheadspec/restheadspec.go

@@ -106,7 +106,7 @@ func SetupMuxRoutes(muxRouter *mux.Router, handler *Handler) {
 		reqAdapter := router.NewHTTPRequest(r)
 		respAdapter := router.NewHTTPResponseWriter(w)
 		handler.Handle(respAdapter, reqAdapter, vars)
-	}).Methods("GET", "PUT", "PATCH", "DELETE")
+	}).Methods("GET", "PUT", "PATCH", "DELETE", "POST")
 
 	// GET for metadata (using HandleGet)
 	muxRouter.HandleFunc("/{schema}/{entity}/metadata", func(w http.ResponseWriter, r *http.Request) {
@@ -189,6 +189,18 @@ func SetupBunRouterRoutes(bunRouter *router.StandardBunRouterAdapter, handler *H
 		return nil
 	})
 
+	r.Handle("POST", "/:schema/:entity/:id", func(w http.ResponseWriter, req bunrouter.Request) error {
+		params := map[string]string{
+			"schema": req.Param("schema"),
+			"entity": req.Param("entity"),
+			"id":     req.Param("id"),
+		}
+		reqAdapter := router.NewBunRouterRequest(req)
+		respAdapter := router.NewHTTPResponseWriter(w)
+		handler.Handle(respAdapter, reqAdapter, params)
+		return nil
+	})
+
 	r.Handle("PUT", "/:schema/:entity/:id", func(w http.ResponseWriter, req bunrouter.Request) error {
 		params := map[string]string{
 			"schema": req.Param("schema"),

tests/crud_test.go

@@ -402,25 +402,41 @@ func testRestHeadSpecCRUD(t *testing.T, serverURL string) {
 		resp := makeRestHeadSpecRequest(t, serverURL, fmt.Sprintf("/restheadspec/departments/%s", deptID), "GET", nil, nil)
 		assert.Equal(t, http.StatusOK, resp.StatusCode)
 
-		// RestHeadSpec may return data directly as array or wrapped in response object
+		// RestHeadSpec may return data directly as array/object or wrapped in response object
 		body, err := io.ReadAll(resp.Body)
 		assert.NoError(t, err, "Failed to read response body")
 
-		// Try to decode as array first (simple format)
+		// Try to decode as array first (simple format - multiple records or disabled SingleRecordAsObject)
 		var dataArray []interface{}
 		if err := json.Unmarshal(body, &dataArray); err == nil {
 			assert.GreaterOrEqual(t, len(dataArray), 1, "Should find department")
-			logger.Info("Department read successfully (simple format): %s", deptID)
+			logger.Info("Department read successfully (simple format - array): %s", deptID)
 			return
 		}
 
-		// Try to decode as standard response object (detail format)
+		// Try to decode as a single object first (simple format with SingleRecordAsObject enabled)
-		var result map[string]interface{}
+		var singleObj map[string]interface{}
-		if err := json.Unmarshal(body, &result); err == nil {
+		if err := json.Unmarshal(body, &singleObj); err == nil {
-			if success, ok := result["success"]; ok && success != nil && success.(bool) {
+			// Check if it's a data object (not a response wrapper)
-				if data, ok := result["data"].([]interface{}); ok {
+			if _, hasSuccess := singleObj["success"]; !hasSuccess {
+				// This is a direct data object (simple format, single record)
+				assert.NotEmpty(t, singleObj, "Should find department")
+				logger.Info("Department read successfully (simple format - single object): %s", deptID)
+				return
+			}
+
+			// Otherwise it's a standard response object (detail format)
+			if success, ok := singleObj["success"]; ok && success != nil && success.(bool) {
+				// Check if data is an array
+				if data, ok := singleObj["data"].([]interface{}); ok {
 					assert.GreaterOrEqual(t, len(data), 1, "Should find department")
-					logger.Info("Department read successfully (detail format): %s", deptID)
+					logger.Info("Department read successfully (detail format - array): %s", deptID)
+					return
+				}
+				// Check if data is a single object (SingleRecordAsObject feature in detail format)
+				if data, ok := singleObj["data"].(map[string]interface{}); ok {
+					assert.NotEmpty(t, data, "Should find department")
+					logger.Info("Department read successfully (detail format - single object): %s", deptID)
 					return
 				}
 			}
@@ -446,25 +462,41 @@ func testRestHeadSpecCRUD(t *testing.T, serverURL string) {
 		resp := makeRestHeadSpecRequest(t, serverURL, "/restheadspec/employees", "GET", nil, headers)
 		assert.Equal(t, http.StatusOK, resp.StatusCode)
 
-		// RestHeadSpec may return data directly as array or wrapped in response object
+		// RestHeadSpec may return data directly as array/object or wrapped in response object
 		body, err := io.ReadAll(resp.Body)
 		assert.NoError(t, err, "Failed to read response body")
 
-		// Try array format first
+		// Try array format first (multiple records or disabled SingleRecordAsObject)
 		var dataArray []interface{}
 		if err := json.Unmarshal(body, &dataArray); err == nil {
 			assert.GreaterOrEqual(t, len(dataArray), 1, "Should find at least one employee")
-			logger.Info("Employees read with filter successfully (simple format), found: %d", len(dataArray))
+			logger.Info("Employees read with filter successfully (simple format - array), found: %d", len(dataArray))
 			return
 		}
 
-		// Try standard response format
+		// Try to decode as a single object (simple format with SingleRecordAsObject enabled)
-		var result map[string]interface{}
+		var singleObj map[string]interface{}
-		if err := json.Unmarshal(body, &result); err == nil {
+		if err := json.Unmarshal(body, &singleObj); err == nil {
-			if success, ok := result["success"]; ok && success != nil && success.(bool) {
+			// Check if it's a data object (not a response wrapper)
-				if data, ok := result["data"].([]interface{}); ok {
+			if _, hasSuccess := singleObj["success"]; !hasSuccess {
+				// This is a direct data object (simple format, single record)
+				assert.NotEmpty(t, singleObj, "Should find at least one employee")
+				logger.Info("Employees read with filter successfully (simple format - single object), found: 1")
+				return
+			}
+
+			// Otherwise it's a standard response object (detail format)
+			if success, ok := singleObj["success"]; ok && success != nil && success.(bool) {
+				// Check if data is an array
+				if data, ok := singleObj["data"].([]interface{}); ok {
 					assert.GreaterOrEqual(t, len(data), 1, "Should find at least one employee")
-					logger.Info("Employees read with filter successfully (detail format), found: %d", len(data))
+					logger.Info("Employees read with filter successfully (detail format - array), found: %d", len(data))
+					return
+				}
+				// Check if data is a single object (SingleRecordAsObject feature in detail format)
+				if data, ok := singleObj["data"].(map[string]interface{}); ok {
+					assert.NotEmpty(t, data, "Should find at least one employee")
+					logger.Info("Employees read with filter successfully (detail format - single object), found: 1")
 					return
 				}
 			}