Better handling of preload where conditions and a few panic changes

pkg/common/adapters/database/bun.go

@@ -9,6 +9,7 @@ import (
 	"github.com/uptrace/bun"
 
 	"github.com/bitechdev/ResolveSpec/pkg/common"
+	"github.com/bitechdev/ResolveSpec/pkg/logger"
 	"github.com/bitechdev/ResolveSpec/pkg/modelregistry"
 	"github.com/bitechdev/ResolveSpec/pkg/reflection"
 )
@@ -43,12 +44,22 @@ func (b *BunAdapter) NewDelete() common.DeleteQuery {
 	return &BunDeleteQuery{query: b.db.NewDelete()}
 }
 
-func (b *BunAdapter) Exec(ctx context.Context, query string, args ...interface{}) (common.Result, error) {
+func (b *BunAdapter) Exec(ctx context.Context, query string, args ...interface{}) (res common.Result, err error) {
+	defer func() {
+		if r := recover(); r != nil {
+			err = logger.HandlePanic("BunAdapter.Exec", r)
+		}
+	}()
 	result, err := b.db.ExecContext(ctx, query, args...)
 	return &BunResult{result: result}, err
 }
 
-func (b *BunAdapter) Query(ctx context.Context, dest interface{}, query string, args ...interface{}) error {
+func (b *BunAdapter) Query(ctx context.Context, dest interface{}, query string, args ...interface{}) (err error) {
+	defer func() {
+		if r := recover(); r != nil {
+			err = logger.HandlePanic("BunAdapter.Query", r)
+		}
+	}()
 	return b.db.NewRaw(query, args...).Scan(ctx, dest)
 }
 
@@ -73,7 +84,12 @@ func (b *BunAdapter) RollbackTx(ctx context.Context) error {
 	return nil
 }
 
-func (b *BunAdapter) RunInTransaction(ctx context.Context, fn func(common.Database) error) error {
+func (b *BunAdapter) RunInTransaction(ctx context.Context, fn func(common.Database) error) (err error) {
+	defer func() {
+		if r := recover(); r != nil {
+			err = logger.HandlePanic("BunAdapter.RunInTransaction", r)
+		}
+	}()
 	return b.db.RunInTx(ctx, &sql.TxOptions{}, func(ctx context.Context, tx bun.Tx) error {
 		// Create adapter with transaction
 		adapter := &BunTxAdapter{tx: tx}
@@ -219,6 +235,11 @@ func (b *BunSelectQuery) Preload(relation string, conditions ...interface{}) com
 
 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 {
+		defer func() {
+			if r := recover(); r != nil {
+				logger.HandlePanic("BunSelectQuery.PreloadRelation", r)
+			}
+		}()
 		if len(apply) == 0 {
 			return sq
 		}
@@ -276,15 +297,38 @@ func (b *BunSelectQuery) Having(having string, args ...interface{}) common.Selec
 	return b
 }
 
-func (b *BunSelectQuery) Scan(ctx context.Context, dest interface{}) error {
+func (b *BunSelectQuery) Scan(ctx context.Context, dest interface{}) (err error) {
+	defer func() {
+		if r := recover(); r != nil {
+			err = logger.HandlePanic("BunSelectQuery.Scan", r)
+		}
+	}()
+	if dest == nil {
+		return fmt.Errorf("destination cannot be nil")
+	}
 	return b.query.Scan(ctx, dest)
 }
 
-func (b *BunSelectQuery) ScanModel(ctx context.Context) error {
+func (b *BunSelectQuery) ScanModel(ctx context.Context) (err error) {
+	defer func() {
+		if r := recover(); r != nil {
+			err = logger.HandlePanic("BunSelectQuery.ScanModel", r)
+		}
+	}()
+	if b.query.GetModel() == nil {
+		return fmt.Errorf("model is nil")
+	}
+
 	return b.query.Scan(ctx)
 }
 
-func (b *BunSelectQuery) Count(ctx context.Context) (int, error) {
+func (b *BunSelectQuery) Count(ctx context.Context) (count int, err error) {
+	defer func() {
+		if r := recover(); r != nil {
+			err = logger.HandlePanic("BunSelectQuery.Count", r)
+			count = 0
+		}
+	}()
 	// If Model() was set, use bun's native Count() which works properly
 	if b.hasModel {
 		count, err := b.query.Count(ctx)
@@ -293,15 +337,20 @@ func (b *BunSelectQuery) Count(ctx context.Context) (int, error) {
 
 	// Otherwise, wrap as subquery to avoid "Model(nil)" error
 	// This is needed when only Table() is set without a model
-	var count int
-	err := b.db.NewSelect().
+	err = b.db.NewSelect().
 		TableExpr("(?) AS subquery", b.query).
 		ColumnExpr("COUNT(*)").
 		Scan(ctx, &count)
 	return count, err
 }
 
-func (b *BunSelectQuery) Exists(ctx context.Context) (bool, error) {
+func (b *BunSelectQuery) Exists(ctx context.Context) (exists bool, err error) {
+	defer func() {
+		if r := recover(); r != nil {
+			err = logger.HandlePanic("BunSelectQuery.Exists", r)
+			exists = false
+		}
+	}()
 	return b.query.Exists(ctx)
 }
 
@@ -320,7 +369,6 @@ func (b *BunInsertQuery) Model(model interface{}) common.InsertQuery {
 
 func (b *BunInsertQuery) Table(table string) common.InsertQuery {
 	if b.hasModel {
-		// If model is set, do not override table name
 		return b
 	}
 	b.query = b.query.Table(table)
@@ -347,7 +395,12 @@ func (b *BunInsertQuery) Returning(columns ...string) common.InsertQuery {
 	return b
 }
 
-func (b *BunInsertQuery) Exec(ctx context.Context) (common.Result, error) {
+func (b *BunInsertQuery) Exec(ctx context.Context) (res common.Result, err error) {
+	defer func() {
+		if r := recover(); r != nil {
+			err = logger.HandlePanic("BunInsertQuery.Exec", r)
+		}
+	}()
 	if b.values != nil && len(b.values) > 0 {
 		if !b.hasModel {
 			// If no model was set, use the values map as the model
@@ -428,7 +481,12 @@ func (b *BunUpdateQuery) Returning(columns ...string) common.UpdateQuery {
 	return b
 }
 
-func (b *BunUpdateQuery) Exec(ctx context.Context) (common.Result, error) {
+func (b *BunUpdateQuery) Exec(ctx context.Context) (res common.Result, err error) {
+	defer func() {
+		if r := recover(); r != nil {
+			err = logger.HandlePanic("BunUpdateQuery.Exec", r)
+		}
+	}()
 	result, err := b.query.Exec(ctx)
 	return &BunResult{result: result}, err
 }
@@ -453,7 +511,12 @@ func (b *BunDeleteQuery) Where(query string, args ...interface{}) common.DeleteQ
 	return b
 }
 
-func (b *BunDeleteQuery) Exec(ctx context.Context) (common.Result, error) {
+func (b *BunDeleteQuery) Exec(ctx context.Context) (res common.Result, err error) {
+	defer func() {
+		if r := recover(); r != nil {
+			err = logger.HandlePanic("BunDeleteQuery.Exec", r)
+		}
+	}()
 	result, err := b.query.Exec(ctx)
 	return &BunResult{result: result}, err
 }

pkg/common/adapters/database/gorm.go

@@ -8,6 +8,7 @@ import (
 	"gorm.io/gorm"
 
 	"github.com/bitechdev/ResolveSpec/pkg/common"
+	"github.com/bitechdev/ResolveSpec/pkg/logger"
 	"github.com/bitechdev/ResolveSpec/pkg/modelregistry"
 	"github.com/bitechdev/ResolveSpec/pkg/reflection"
 )
@@ -38,12 +39,22 @@ func (g *GormAdapter) NewDelete() common.DeleteQuery {
 	return &GormDeleteQuery{db: g.db}
 }
 
-func (g *GormAdapter) Exec(ctx context.Context, query string, args ...interface{}) (common.Result, error) {
+func (g *GormAdapter) Exec(ctx context.Context, query string, args ...interface{}) (res common.Result, err error) {
+	defer func() {
+		if r := recover(); r != nil {
+			err = logger.HandlePanic("GormAdapter.Exec", r)
+		}
+	}()
 	result := g.db.WithContext(ctx).Exec(query, args...)
 	return &GormResult{result: result}, result.Error
 }
 
-func (g *GormAdapter) Query(ctx context.Context, dest interface{}, query string, args ...interface{}) error {
+func (g *GormAdapter) Query(ctx context.Context, dest interface{}, query string, args ...interface{}) (err error) {
+	defer func() {
+		if r := recover(); r != nil {
+			err = logger.HandlePanic("GormAdapter.Query", r)
+		}
+	}()
 	return g.db.WithContext(ctx).Raw(query, args...).Find(dest).Error
 }
 
@@ -63,7 +74,12 @@ func (g *GormAdapter) RollbackTx(ctx context.Context) error {
 	return g.db.WithContext(ctx).Rollback().Error
 }
 
-func (g *GormAdapter) RunInTransaction(ctx context.Context, fn func(common.Database) error) error {
+func (g *GormAdapter) RunInTransaction(ctx context.Context, fn func(common.Database) error) (err error) {
+	defer func() {
+		if r := recover(); r != nil {
+			err = logger.HandlePanic("GormAdapter.RunInTransaction", r)
+		}
+	}()
 	return g.db.WithContext(ctx).Transaction(func(tx *gorm.DB) error {
 		adapter := &GormAdapter{db: tx}
 		return fn(adapter)
@@ -255,26 +271,48 @@ func (g *GormSelectQuery) Having(having string, args ...interface{}) common.Sele
 	return g
 }
 
-func (g *GormSelectQuery) Scan(ctx context.Context, dest interface{}) error {
+func (g *GormSelectQuery) Scan(ctx context.Context, dest interface{}) (err error) {
+	defer func() {
+		if r := recover(); r != nil {
+			err = logger.HandlePanic("GormSelectQuery.Scan", r)
+		}
+	}()
 	return g.db.WithContext(ctx).Find(dest).Error
 }
 
-func (g *GormSelectQuery) ScanModel(ctx context.Context) error {
+func (g *GormSelectQuery) ScanModel(ctx context.Context) (err error) {
+	defer func() {
+		if r := recover(); r != nil {
+			err = logger.HandlePanic("GormSelectQuery.ScanModel", r)
+		}
+	}()
 	if g.db.Statement.Model == nil {
 		return fmt.Errorf("ScanModel requires Model() to be set before scanning")
 	}
 	return g.db.WithContext(ctx).Find(g.db.Statement.Model).Error
 }
 
-func (g *GormSelectQuery) Count(ctx context.Context) (int, error) {
-	var count int64
-	err := g.db.WithContext(ctx).Count(&count).Error
-	return int(count), err
+func (g *GormSelectQuery) Count(ctx context.Context) (count int, err error) {
+	defer func() {
+		if r := recover(); r != nil {
+			err = logger.HandlePanic("GormSelectQuery.Count", r)
+			count = 0
+		}
+	}()
+	var count64 int64
+	err = g.db.WithContext(ctx).Count(&count64).Error
+	return int(count64), err
 }
 
-func (g *GormSelectQuery) Exists(ctx context.Context) (bool, error) {
+func (g *GormSelectQuery) Exists(ctx context.Context) (exists bool, err error) {
+	defer func() {
+		if r := recover(); r != nil {
+			err = logger.HandlePanic("GormSelectQuery.Exists", r)
+			exists = false
+		}
+	}()
 	var count int64
-	err := g.db.WithContext(ctx).Limit(1).Count(&count).Error
+	err = g.db.WithContext(ctx).Limit(1).Count(&count).Error
 	return count > 0, err
 }
 
@@ -314,7 +352,12 @@ func (g *GormInsertQuery) Returning(columns ...string) common.InsertQuery {
 	return g
 }
 
-func (g *GormInsertQuery) Exec(ctx context.Context) (common.Result, error) {
+func (g *GormInsertQuery) Exec(ctx context.Context) (res common.Result, err error) {
+	defer func() {
+		if r := recover(); r != nil {
+			err = logger.HandlePanic("GormInsertQuery.Exec", r)
+		}
+	}()
 	var result *gorm.DB
 	switch {
 	case g.model != nil:
@@ -401,7 +444,12 @@ func (g *GormUpdateQuery) Returning(columns ...string) common.UpdateQuery {
 	return g
 }
 
-func (g *GormUpdateQuery) Exec(ctx context.Context) (common.Result, error) {
+func (g *GormUpdateQuery) Exec(ctx context.Context) (res common.Result, err error) {
+	defer func() {
+		if r := recover(); r != nil {
+			err = logger.HandlePanic("GormUpdateQuery.Exec", r)
+		}
+	}()
 	result := g.db.WithContext(ctx).Updates(g.updates)
 	return &GormResult{result: result}, result.Error
 }
@@ -428,7 +476,12 @@ func (g *GormDeleteQuery) Where(query string, args ...interface{}) common.Delete
 	return g
 }
 
-func (g *GormDeleteQuery) Exec(ctx context.Context) (common.Result, error) {
+func (g *GormDeleteQuery) Exec(ctx context.Context) (res common.Result, err error) {
+	defer func() {
+		if r := recover(); r != nil {
+			err = logger.HandlePanic("GormDeleteQuery.Exec", r)
+		}
+	}()
 	result := g.db.WithContext(ctx).Delete(g.model)
 	return &GormResult{result: result}, result.Error
 }

pkg/logger/logger.go

@@ -103,3 +103,18 @@ func CatchPanicCallback(location string, cb func(err any)) {
 func CatchPanic(location string) {
 	CatchPanicCallback(location, nil)
 }
+
+// HandlePanic logs a panic and returns it as an error
+// This should be called with the result of recover() from a deferred function
+// Example usage:
+//
+//	defer func() {
+//	    if r := recover(); r != nil {
+//	        err = logger.HandlePanic("MethodName", r)
+//	    }
+//	}()
+func HandlePanic(methodName string, r any) error {
+	stack := debug.Stack()
+	Error("Panic in %s: %v\nStack trace:\n%s", methodName, r, string(stack))
+	return fmt.Errorf("panic in %s: %v", methodName, r)
+}

pkg/resolvespec/handler.go

@@ -1105,6 +1105,69 @@ type relationshipInfo struct {
 	relatedModel interface{}
 }
 
+// validateAndFixPreloadWhere validates that the WHERE clause for a preload contains
+// the relation prefix (alias). If not present, it attempts to add it to column references.
+// Returns the fixed WHERE clause and an error if it cannot be safely fixed.
+func (h *Handler) validateAndFixPreloadWhere(where string, relationName string) (string, error) {
+	if where == "" {
+		return where, nil
+	}
+
+	// Check if the relation name is already present in the WHERE clause
+	lowerWhere := strings.ToLower(where)
+	lowerRelation := strings.ToLower(relationName)
+
+	// Check for patterns like "relation.", "relation ", or just "relation" followed by a dot
+	if strings.Contains(lowerWhere, lowerRelation+".") ||
+	   strings.Contains(lowerWhere, "`"+lowerRelation+"`.") ||
+	   strings.Contains(lowerWhere, "\""+lowerRelation+"\".") {
+		// Relation prefix is already present
+		return where, nil
+	}
+
+	// If the WHERE clause is complex (contains OR, parentheses, subqueries, etc.),
+	// we can't safely auto-fix it - require explicit prefix
+	if strings.Contains(lowerWhere, " or ") ||
+	   strings.Contains(where, "(") ||
+	   strings.Contains(where, ")") {
+		return "", fmt.Errorf("preload WHERE condition must reference the relation '%s' (e.g., '%s.column_name'). Complex WHERE clauses with OR/parentheses must explicitly use the relation prefix", relationName, relationName)
+	}
+
+	// Try to add the relation prefix to simple column references
+	// This handles basic cases like "column = value" or "column = value AND other_column = value"
+	// Split by AND to handle multiple conditions (case-insensitive)
+	originalConditions := strings.Split(where, " AND ")
+
+	// If uppercase split didn't work, try lowercase
+	if len(originalConditions) == 1 {
+		originalConditions = strings.Split(where, " and ")
+	}
+
+	fixedConditions := make([]string, 0, len(originalConditions))
+
+	for _, cond := range originalConditions {
+		cond = strings.TrimSpace(cond)
+		if cond == "" {
+			continue
+		}
+
+		// Check if this condition already has a table prefix (contains a dot)
+		if strings.Contains(cond, ".") {
+			fixedConditions = append(fixedConditions, cond)
+			continue
+		}
+
+		// Add relation prefix to the column name
+		// This prefixes the entire condition with "relationName."
+		fixedCond := fmt.Sprintf("%s.%s", relationName, cond)
+		fixedConditions = append(fixedConditions, fixedCond)
+	}
+
+	fixedWhere := strings.Join(fixedConditions, " AND ")
+	logger.Debug("Auto-fixed preload WHERE clause: '%s' -> '%s'", where, fixedWhere)
+	return fixedWhere, nil
+}
+
 func (h *Handler) applyPreloads(model interface{}, query common.SelectQuery, preloads []common.PreloadOption) common.SelectQuery {
 	modelType := reflect.TypeOf(model)
 
@@ -1132,10 +1195,15 @@ func (h *Handler) applyPreloads(model interface{}, query common.SelectQuery, pre
 		// ORMs like GORM and Bun expect the struct field name, not the JSON name
 		relationFieldName := relInfo.fieldName
 
-		// 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
-		// Apply preloading
+		// Validate and fix WHERE clause to ensure it contains the relation prefix
+		if len(preload.Where) > 0 {
+			fixedWhere, err := h.validateAndFixPreloadWhere(preload.Where, relationFieldName)
+			if err != nil {
+				logger.Error("Invalid preload WHERE clause for relation '%s': %v", relationFieldName, err)
+				panic(fmt.Errorf("invalid preload WHERE clause for relation '%s': %w", relationFieldName, err))
+			}
+			preload.Where = fixedWhere
+		}
 
 		logger.Debug("Applying preload: %s", relationFieldName)
 		query = query.PreloadRelation(relationFieldName, func(sq common.SelectQuery) common.SelectQuery {

pkg/restheadspec/context.go

@@ -13,6 +13,7 @@ const (
 	contextKeyTableName contextKey = "tableName"
 	contextKeyModel     contextKey = "model"
 	contextKeyModelPtr  contextKey = "modelPtr"
+	contextKeyOptions   contextKey = "options"
 )
 
 // WithSchema adds schema to context
@@ -74,12 +75,28 @@ func GetModelPtr(ctx context.Context) interface{} {
 	return ctx.Value(contextKeyModelPtr)
 }
 
+// WithOptions adds request options to context
+func WithOptions(ctx context.Context, options ExtendedRequestOptions) context.Context {
+	return context.WithValue(ctx, contextKeyOptions, options)
+}
+
+// GetOptions retrieves request options from context
+func GetOptions(ctx context.Context) *ExtendedRequestOptions {
+	if v := ctx.Value(contextKeyOptions); v != nil {
+		if opts, ok := v.(ExtendedRequestOptions); ok {
+			return &opts
+		}
+	}
+	return nil
+}
+
 // WithRequestData adds all request-scoped data to context at once
-func WithRequestData(ctx context.Context, schema, entity, tableName string, model, modelPtr interface{}) context.Context {
+func WithRequestData(ctx context.Context, schema, entity, tableName string, model, modelPtr interface{}, options ExtendedRequestOptions) context.Context {
 	ctx = WithSchema(ctx, schema)
 	ctx = WithEntity(ctx, entity)
 	ctx = WithTableName(ctx, tableName)
 	ctx = WithModel(ctx, model)
 	ctx = WithModelPtr(ctx, modelPtr)
+	ctx = WithOptions(ctx, options)
 	return ctx
 }

pkg/restheadspec/handler.go

@@ -65,9 +65,6 @@ func (h *Handler) Handle(w common.ResponseWriter, r common.Request, params map[s
 	entity := params["entity"]
 	id := params["id"]
 
-	// Parse options from headers (now returns ExtendedRequestOptions)
-	options := h.parseOptionsFromHeaders(r)
-
 	// Determine operation based on HTTP method
 	method := r.Method()
 
@@ -104,13 +101,16 @@ func (h *Handler) Handle(w common.ResponseWriter, r common.Request, params map[s
 	modelPtr := reflect.New(reflect.TypeOf(model)).Interface()
 	tableName := h.getTableName(schema, entity, model)
 
-	// Add request-scoped data to context
-	ctx = WithRequestData(ctx, schema, entity, tableName, model, modelPtr)
+	// Parse options from headers - this now includes relation name resolution
+	options := h.parseOptionsFromHeaders(r, model)
 
 	// Validate and filter columns in options (log warnings for invalid columns)
 	validator := common.NewColumnValidator(model)
 	options = filterExtendedOptions(validator, options)
 
+	// Add request-scoped data to context (including options)
+	ctx = WithRequestData(ctx, schema, entity, tableName, model, modelPtr, options)
+
 	switch method {
 	case "GET":
 		if id != "" {
@@ -200,6 +200,69 @@ func (h *Handler) HandleGet(w common.ResponseWriter, r common.Request, params ma
 
 // parseOptionsFromHeaders is now implemented in headers.go
 
+// validateAndFixPreloadWhere validates that the WHERE clause for a preload contains
+// the relation prefix (alias). If not present, it attempts to add it to column references.
+// Returns the fixed WHERE clause and an error if it cannot be safely fixed.
+func (h *Handler) validateAndFixPreloadWhere(where string, relationName string) (string, error) {
+	if where == "" {
+		return where, nil
+	}
+
+	// Check if the relation name is already present in the WHERE clause
+	lowerWhere := strings.ToLower(where)
+	lowerRelation := strings.ToLower(relationName)
+
+	// Check for patterns like "relation.", "relation ", or just "relation" followed by a dot
+	if strings.Contains(lowerWhere, lowerRelation+".") ||
+	   strings.Contains(lowerWhere, "`"+lowerRelation+"`.") ||
+	   strings.Contains(lowerWhere, "\""+lowerRelation+"\".") {
+		// Relation prefix is already present
+		return where, nil
+	}
+
+	// If the WHERE clause is complex (contains OR, parentheses, subqueries, etc.),
+	// we can't safely auto-fix it - require explicit prefix
+	if strings.Contains(lowerWhere, " or ") ||
+	   strings.Contains(where, "(") ||
+	   strings.Contains(where, ")") {
+		return "", fmt.Errorf("preload WHERE condition must reference the relation '%s' (e.g., '%s.column_name'). Complex WHERE clauses with OR/parentheses must explicitly use the relation prefix", relationName, relationName)
+	}
+
+	// Try to add the relation prefix to simple column references
+	// This handles basic cases like "column = value" or "column = value AND other_column = value"
+	// Split by AND to handle multiple conditions (case-insensitive)
+	originalConditions := strings.Split(where, " AND ")
+
+	// If uppercase split didn't work, try lowercase
+	if len(originalConditions) == 1 {
+		originalConditions = strings.Split(where, " and ")
+	}
+
+	fixedConditions := make([]string, 0, len(originalConditions))
+
+	for _, cond := range originalConditions {
+		cond = strings.TrimSpace(cond)
+		if cond == "" {
+			continue
+		}
+
+		// Check if this condition already has a table prefix (contains a dot)
+		if strings.Contains(cond, ".") {
+			fixedConditions = append(fixedConditions, cond)
+			continue
+		}
+
+		// Add relation prefix to the column name
+		// This prefixes the entire condition with "relationName."
+		fixedCond := fmt.Sprintf("%s.%s", relationName, cond)
+		fixedConditions = append(fixedConditions, fixedCond)
+	}
+
+	fixedWhere := strings.Join(fixedConditions, " AND ")
+	logger.Debug("Auto-fixed preload WHERE clause: '%s' -> '%s'", where, fixedWhere)
+	return fixedWhere, nil
+}
+
 func (h *Handler) handleRead(ctx context.Context, w common.ResponseWriter, id string, options ExtendedRequestOptions) {
 	// Capture panics and return error response
 	defer func() {
@@ -344,6 +407,19 @@ func (h *Handler) handleRead(ctx context.Context, w common.ResponseWriter, id st
 	for idx := range options.Preload {
 		preload := options.Preload[idx]
 		logger.Debug("Applying preload: %s", preload.Relation)
+
+		// Validate and fix WHERE clause to ensure it contains the relation prefix
+		if len(preload.Where) > 0 {
+			fixedWhere, err := h.validateAndFixPreloadWhere(preload.Where, preload.Relation)
+			if err != nil {
+				logger.Error("Invalid preload WHERE clause for relation '%s': %v", preload.Relation, err)
+				h.sendError(w, http.StatusBadRequest, "invalid_preload_where",
+					fmt.Sprintf("Invalid preload WHERE clause for relation '%s'", preload.Relation), err)
+				return
+			}
+			preload.Where = fixedWhere
+		}
+
 		query = query.PreloadRelation(preload.Relation, func(sq common.SelectQuery) common.SelectQuery {
 			if len(preload.OmitColumns) > 0 {
 				allCols := reflection.GetModelColumns(model)

pkg/restheadspec/headers.go

@@ -99,7 +99,8 @@ func DecodeParam(pStr string) (string, error) {
 }
 
 // parseOptionsFromHeaders parses all request options from HTTP headers
-func (h *Handler) parseOptionsFromHeaders(r common.Request) ExtendedRequestOptions {
+// If model is provided, it will resolve table names to field names in preload/expand options
+func (h *Handler) parseOptionsFromHeaders(r common.Request, model interface{}) ExtendedRequestOptions {
 	options := ExtendedRequestOptions{
 		RequestOptions: common.RequestOptions{
 			Filters: make([]common.FilterOption, 0),
@@ -225,6 +226,11 @@ func (h *Handler) parseOptionsFromHeaders(r common.Request) ExtendedRequestOptio
 		}
 	}
 
+	// Resolve relation names (convert table names to field names) if model is provided
+	if model != nil {
+		h.resolveRelationNamesInOptions(&options, model)
+	}
+
 	return options
 }
 
@@ -655,6 +661,192 @@ func (h *Handler) processXFilesRelations(xfiles *XFiles, options *ExtendedReques
 	}
 }
 
+// resolveRelationNamesInOptions resolves all table names to field names in preload options
+// This is called internally by parseOptionsFromHeaders when a model is provided
+func (h *Handler) resolveRelationNamesInOptions(options *ExtendedRequestOptions, model interface{}) {
+	if options == nil || model == nil {
+		return
+	}
+
+	// Resolve relation names in all preload options
+	for i := range options.Preload {
+		preload := &options.Preload[i]
+
+		// Split the relation path (e.g., "parent.child.grandchild")
+		parts := strings.Split(preload.Relation, ".")
+		resolvedParts := make([]string, 0, len(parts))
+
+		// Resolve each part of the path
+		currentModel := model
+		for _, part := range parts {
+			resolvedPart := h.resolveRelationName(currentModel, part)
+			resolvedParts = append(resolvedParts, resolvedPart)
+
+			// Try to get the model type for the next level
+			// This allows nested resolution
+			if nextModel := h.getRelationModel(currentModel, resolvedPart); nextModel != nil {
+				currentModel = nextModel
+			}
+		}
+
+		// Update the relation path with resolved names
+		resolvedPath := strings.Join(resolvedParts, ".")
+		if resolvedPath != preload.Relation {
+			logger.Debug("Resolved relation path '%s' -> '%s'", preload.Relation, resolvedPath)
+			preload.Relation = resolvedPath
+		}
+	}
+
+	// Resolve relation names in expand options
+	for i := range options.Expand {
+		expand := &options.Expand[i]
+		resolved := h.resolveRelationName(model, expand.Relation)
+		if resolved != expand.Relation {
+			logger.Debug("Resolved expand relation '%s' -> '%s'", expand.Relation, resolved)
+			expand.Relation = resolved
+		}
+	}
+}
+
+// getRelationModel gets the model type for a relation field
+func (h *Handler) getRelationModel(model interface{}, fieldName string) interface{} {
+	if model == nil || fieldName == "" {
+		return nil
+	}
+
+	modelType := reflect.TypeOf(model)
+	if modelType == nil {
+		return nil
+	}
+
+	if modelType.Kind() == reflect.Ptr {
+		modelType = modelType.Elem()
+	}
+
+	if modelType == nil || modelType.Kind() != reflect.Struct {
+		return nil
+	}
+
+	// Find the field
+	field, found := modelType.FieldByName(fieldName)
+	if !found {
+		return nil
+	}
+
+	// Get the target type
+	targetType := field.Type
+	if targetType == nil {
+		return nil
+	}
+
+	if targetType.Kind() == reflect.Slice {
+		targetType = targetType.Elem()
+		if targetType == nil {
+			return nil
+		}
+	}
+	if targetType.Kind() == reflect.Ptr {
+		targetType = targetType.Elem()
+		if targetType == nil {
+			return nil
+		}
+	}
+
+	if targetType.Kind() != reflect.Struct {
+		return nil
+	}
+
+	// Create a zero value of the target type
+	return reflect.New(targetType).Elem().Interface()
+}
+
+// resolveRelationName resolves a relation name or table name to the actual field name in the model
+// If the input is already a field name, it returns it as-is
+// If the input is a table name, it looks up the corresponding relation field
+func (h *Handler) resolveRelationName(model interface{}, nameOrTable string) string {
+	if model == nil || nameOrTable == "" {
+		return nameOrTable
+	}
+
+	modelType := reflect.TypeOf(model)
+	if modelType == nil {
+		return nameOrTable
+	}
+
+	// Dereference pointer if needed
+	if modelType.Kind() == reflect.Ptr {
+		modelType = modelType.Elem()
+	}
+
+	// Check again after dereferencing
+	if modelType == nil {
+		return nameOrTable
+	}
+
+	// Ensure it's a struct
+	if modelType.Kind() != reflect.Struct {
+		return nameOrTable
+	}
+
+	// First, check if the input matches a field name directly
+	for i := 0; i < modelType.NumField(); i++ {
+		field := modelType.Field(i)
+		if field.Name == nameOrTable {
+			// It's already a field name
+			logger.Debug("Input '%s' is a field name", nameOrTable)
+			return nameOrTable
+		}
+	}
+
+	// If not found as a field name, try to look it up as a table name
+	normalizedInput := strings.ToLower(strings.ReplaceAll(nameOrTable, "_", ""))
+
+	for i := 0; i < modelType.NumField(); i++ {
+		field := modelType.Field(i)
+		fieldType := field.Type
+
+		// Check if it's a slice or pointer to a struct
+		var targetType reflect.Type
+		if fieldType.Kind() == reflect.Slice {
+			targetType = fieldType.Elem()
+		} else if fieldType.Kind() == reflect.Ptr {
+			targetType = fieldType.Elem()
+		}
+
+		if targetType != nil {
+			// Dereference pointer if the slice contains pointers
+			if targetType.Kind() == reflect.Ptr {
+				targetType = targetType.Elem()
+			}
+
+			// Check if it's a struct type
+			if targetType.Kind() == reflect.Struct {
+				// Get the type name and normalize it
+				typeName := targetType.Name()
+
+				// Extract the table name from type name
+				// Patterns: ModelCoreMastertaskitem -> mastertaskitem
+				//           ModelMastertaskitem -> mastertaskitem
+				normalizedTypeName := strings.ToLower(typeName)
+
+				// Remove common prefixes like "model", "modelcore", etc.
+				normalizedTypeName = strings.TrimPrefix(normalizedTypeName, "modelcore")
+				normalizedTypeName = strings.TrimPrefix(normalizedTypeName, "model")
+
+				// Compare normalized names
+				if normalizedTypeName == normalizedInput {
+					logger.Debug("Resolved table name '%s' to field '%s' (type: %s)", nameOrTable, field.Name, typeName)
+					return field.Name
+				}
+			}
+		}
+	}
+
+	// If no match found, return the original input
+	logger.Debug("No field found for '%s', using as-is", nameOrTable)
+	return nameOrTable
+}
+
 // addXFilesPreload converts an XFiles relation into a PreloadOption
 // and recursively processes its children
 func (h *Handler) addXFilesPreload(xfile *XFiles, options *ExtendedRequestOptions, basePath string) {
@@ -662,7 +854,8 @@ func (h *Handler) addXFilesPreload(xfile *XFiles, options *ExtendedRequestOption
 		return
 	}
 
-	// Determine the relation path
+	// Store the table name as-is for now - it will be resolved to field name later
+	// when we have the model instance available
 	relationPath := xfile.TableName
 	if basePath != "" {
 		relationPath = basePath + "." + xfile.TableName