chore(release): update package version to 1.0.68

Existing databases that already ran an old migration kept stale NOT
NULL constraints and mismatched column types/defaults, because the
schema writer only emitted idempotent ADD COLUMN IF NOT EXISTS guards
and never altered columns that already existed.

- Emit guarded ALTER COLUMN ... SET/DROP NOT NULL when a column's
  nullability differs from the model.
- Emit guarded ALTER COLUMN ... TYPE, falling back to renaming the old
  column and adding a fresh one when the in-place conversion fails.
- Emit guarded ALTER COLUMN ... SET/DROP DEFAULT for default drift.
- Collapse the previously duplicated plain/guarded templates so
  WriteSchema (full-schema, live-state-checking) and WriteMigration
  (diff-based) share the same guarded SQL templates and Go helpers
  instead of maintaining the logic twice.

linux/arch/PKGBUILD

@@ -1,6 +1,6 @@
 # Maintainer: Hein (Warky Devs) <hein@warky.dev>
 pkgname=relspec
-pkgver=1.0.65
+pkgver=1.0.68
 pkgrel=1
 pkgdesc="RelSpec is a comprehensive database relations management tool that reads, transforms, and writes database table specifications across multiple formats and ORMs."
 arch=('x86_64' 'aarch64')

linux/centos/relspec.spec

@@ -1,5 +1,5 @@
 Name:           relspec
-Version:        1.0.65
+Version:        1.0.68
 Release:        1%{?dist}
 Summary:        RelSpec is a comprehensive database relations management tool that reads, transforms, and writes database table specifications across multiple formats and ORMs.
 

pkg/diff/diff.go

@@ -2,10 +2,22 @@ package diff
 
 import (
 	"reflect"
+	"sort"
 
 	"git.warky.dev/wdevs/relspecgo/pkg/models"
 )
 
+// sortedKeys returns a map's keys sorted alphabetically, so callers get a
+// deterministic iteration order instead of Go's randomized map order.
+func sortedKeys[T any](m map[string]T) []string {
+	keys := make([]string, 0, len(m))
+	for k := range m {
+		keys = append(keys, k)
+	}
+	sort.Strings(keys)
+	return keys
+}
+
 // CompareDatabases compares two database models and returns the differences
 func CompareDatabases(source, target *models.Database) *DiffResult {
 	result := &DiffResult{
@@ -34,7 +46,8 @@ func compareSchemas(source, target []*models.Schema) *SchemaDiff {
 	}
 
 	// Find missing and modified schemas
-	for name, srcSchema := range sourceMap {
+	for _, name := range sortedKeys(sourceMap) {
+		srcSchema := sourceMap[name]
 		if tgtSchema, exists := targetMap[name]; !exists {
 			diff.Missing = append(diff.Missing, srcSchema)
 		} else {
@@ -45,7 +58,8 @@ func compareSchemas(source, target []*models.Schema) *SchemaDiff {
 	}
 
 	// Find extra schemas
-	for name, tgtSchema := range targetMap {
+	for _, name := range sortedKeys(targetMap) {
+		tgtSchema := targetMap[name]
 		if _, exists := sourceMap[name]; !exists {
 			diff.Extra = append(diff.Extra, tgtSchema)
 		}
@@ -106,7 +120,8 @@ func compareTables(source, target []*models.Table) *TableDiff {
 	}
 
 	// Find missing and modified tables
-	for name, srcTable := range sourceMap {
+	for _, name := range sortedKeys(sourceMap) {
+		srcTable := sourceMap[name]
 		if tgtTable, exists := targetMap[name]; !exists {
 			diff.Missing = append(diff.Missing, srcTable)
 		} else {
@@ -117,7 +132,8 @@ func compareTables(source, target []*models.Table) *TableDiff {
 	}
 
 	// Find extra tables
-	for name, tgtTable := range targetMap {
+	for _, name := range sortedKeys(targetMap) {
+		tgtTable := targetMap[name]
 		if _, exists := sourceMap[name]; !exists {
 			diff.Extra = append(diff.Extra, tgtTable)
 		}
@@ -176,7 +192,8 @@ func compareColumns(source, target map[string]*models.Column) *ColumnDiff {
 	}
 
 	// Find missing and modified columns
-	for name, srcCol := range source {
+	for _, name := range sortedKeys(source) {
+		srcCol := source[name]
 		if tgtCol, exists := target[name]; !exists {
 			diff.Missing = append(diff.Missing, srcCol)
 		} else {
@@ -192,7 +209,8 @@ func compareColumns(source, target map[string]*models.Column) *ColumnDiff {
 	}
 
 	// Find extra columns
-	for name, tgtCol := range target {
+	for _, name := range sortedKeys(target) {
+		tgtCol := target[name]
 		if _, exists := source[name]; !exists {
 			diff.Extra = append(diff.Extra, tgtCol)
 		}
@@ -240,7 +258,8 @@ func compareIndexes(source, target map[string]*models.Index) *IndexDiff {
 	}
 
 	// Find missing and modified indexes
-	for name, srcIdx := range source {
+	for _, name := range sortedKeys(source) {
+		srcIdx := source[name]
 		if tgtIdx, exists := target[name]; !exists {
 			diff.Missing = append(diff.Missing, srcIdx)
 		} else {
@@ -256,7 +275,8 @@ func compareIndexes(source, target map[string]*models.Index) *IndexDiff {
 	}
 
 	// Find extra indexes
-	for name, tgtIdx := range target {
+	for _, name := range sortedKeys(target) {
+		tgtIdx := target[name]
 		if _, exists := source[name]; !exists {
 			diff.Extra = append(diff.Extra, tgtIdx)
 		}
@@ -292,7 +312,8 @@ func compareConstraints(source, target map[string]*models.Constraint) *Constrain
 	}
 
 	// Find missing and modified constraints
-	for name, srcCon := range source {
+	for _, name := range sortedKeys(source) {
+		srcCon := source[name]
 		if tgtCon, exists := target[name]; !exists {
 			diff.Missing = append(diff.Missing, srcCon)
 		} else {
@@ -308,7 +329,8 @@ func compareConstraints(source, target map[string]*models.Constraint) *Constrain
 	}
 
 	// Find extra constraints
-	for name, tgtCon := range target {
+	for _, name := range sortedKeys(target) {
+		tgtCon := target[name]
 		if _, exists := source[name]; !exists {
 			diff.Extra = append(diff.Extra, tgtCon)
 		}
@@ -350,7 +372,8 @@ func compareRelationships(source, target map[string]*models.Relationship) *Relat
 	}
 
 	// Find missing and modified relationships
-	for name, srcRel := range source {
+	for _, name := range sortedKeys(source) {
+		srcRel := source[name]
 		if tgtRel, exists := target[name]; !exists {
 			diff.Missing = append(diff.Missing, srcRel)
 		} else {
@@ -366,7 +389,8 @@ func compareRelationships(source, target map[string]*models.Relationship) *Relat
 	}
 
 	// Find extra relationships
-	for name, tgtRel := range target {
+	for _, name := range sortedKeys(target) {
+		tgtRel := target[name]
 		if _, exists := source[name]; !exists {
 			diff.Extra = append(diff.Extra, tgtRel)
 		}
@@ -415,7 +439,8 @@ func compareViews(source, target []*models.View) *ViewDiff {
 	}
 
 	// Find missing and modified views
-	for name, srcView := range sourceMap {
+	for _, name := range sortedKeys(sourceMap) {
+		srcView := sourceMap[name]
 		if tgtView, exists := targetMap[name]; !exists {
 			diff.Missing = append(diff.Missing, srcView)
 		} else {
@@ -431,7 +456,8 @@ func compareViews(source, target []*models.View) *ViewDiff {
 	}
 
 	// Find extra views
-	for name, tgtView := range targetMap {
+	for _, name := range sortedKeys(targetMap) {
+		tgtView := targetMap[name]
 		if _, exists := sourceMap[name]; !exists {
 			diff.Extra = append(diff.Extra, tgtView)
 		}
@@ -468,7 +494,8 @@ func compareSequences(source, target []*models.Sequence) *SequenceDiff {
 	}
 
 	// Find missing and modified sequences
-	for name, srcSeq := range sourceMap {
+	for _, name := range sortedKeys(sourceMap) {
+		srcSeq := sourceMap[name]
 		if tgtSeq, exists := targetMap[name]; !exists {
 			diff.Missing = append(diff.Missing, srcSeq)
 		} else {
@@ -484,7 +511,8 @@ func compareSequences(source, target []*models.Sequence) *SequenceDiff {
 	}
 
 	// Find extra sequences
-	for name, tgtSeq := range targetMap {
+	for _, name := range sortedKeys(targetMap) {
+		tgtSeq := targetMap[name]
 		if _, exists := sourceMap[name]; !exists {
 			diff.Extra = append(diff.Extra, tgtSeq)
 		}

pkg/diff/diff_test.go

@@ -1,6 +1,7 @@
 package diff
 
 import (
+	"reflect"
 	"testing"
 
 	"git.warky.dev/wdevs/relspecgo/pkg/models"
@@ -140,6 +141,46 @@ func TestCompareColumns(t *testing.T) {
 	}
 }
 
+// TestCompareColumns_Deterministic verifies that Missing/Extra entries are
+// always reported in the same (alphabetical) order across repeated calls,
+// instead of following Go's randomized map iteration order over the
+// source/target column maps.
+func TestCompareColumns_Deterministic(t *testing.T) {
+	source := map[string]*models.Column{
+		"zeta":  {Name: "zeta", Type: "text"},
+		"alpha": {Name: "alpha", Type: "text"},
+		"mu":    {Name: "mu", Type: "text"},
+	}
+	target := map[string]*models.Column{
+		"omega":   {Name: "omega", Type: "text"},
+		"delta":   {Name: "delta", Type: "text"},
+		"charlie": {Name: "charlie", Type: "text"},
+	}
+
+	wantMissing := []string{"alpha", "mu", "zeta"}
+	wantExtra := []string{"charlie", "delta", "omega"}
+
+	for i := 0; i < 25; i++ {
+		got := compareColumns(source, target)
+
+		gotMissing := make([]string, len(got.Missing))
+		for j, c := range got.Missing {
+			gotMissing[j] = c.Name
+		}
+		gotExtra := make([]string, len(got.Extra))
+		for j, c := range got.Extra {
+			gotExtra[j] = c.Name
+		}
+
+		if !reflect.DeepEqual(gotMissing, wantMissing) {
+			t.Fatalf("compareColumns() Missing = %v, want %v (run %d)", gotMissing, wantMissing, i)
+		}
+		if !reflect.DeepEqual(gotExtra, wantExtra) {
+			t.Fatalf("compareColumns() Extra = %v, want %v (run %d)", gotExtra, wantExtra, i)
+		}
+	}
+}
+
 func TestCompareColumnDetails(t *testing.T) {
 	tests := []struct {
 		name   string

pkg/inspector/inspector.go

@@ -2,6 +2,7 @@ package inspector
 
 import (
 	"fmt"
+	"sort"
 	"time"
 
 	"git.warky.dev/wdevs/relspecgo/pkg/models"
@@ -54,8 +55,15 @@ func NewInspector(db *models.Database, config *Config) *Inspector {
 func (i *Inspector) Inspect() (*InspectorReport, error) {
 	results := []ValidationResult{}
 
-	// Run all enabled validators
-	for ruleName, rule := range i.config.Rules {
+	// Run all enabled validators in deterministic (alphabetical) rule-name order
+	ruleNames := make([]string, 0, len(i.config.Rules))
+	for ruleName := range i.config.Rules {
+		ruleNames = append(ruleNames, ruleName)
+	}
+	sort.Strings(ruleNames)
+
+	for _, ruleName := range ruleNames {
+		rule := i.config.Rules[ruleName]
 		if !rule.IsEnabled() {
 			continue
 		}

pkg/inspector/inspector_test.go

@@ -51,6 +51,45 @@ func TestInspect(t *testing.T) {
 	}
 }
 
+// TestInspect_Deterministic verifies that repeated Inspect() calls against
+// the same database and config produce violations in the same order, instead
+// of following Go's randomized map iteration order over config.Rules and the
+// per-table Columns/Constraints/Indexes maps.
+func TestInspect_Deterministic(t *testing.T) {
+	db := createTestDatabase()
+	config := GetDefaultConfig()
+
+	inspector := NewInspector(db, config)
+
+	first, err := inspector.Inspect()
+	if err != nil {
+		t.Fatalf("Inspect() returned error: %v", err)
+	}
+
+	wantOrder := make([]string, len(first.Violations))
+	for i, v := range first.Violations {
+		wantOrder[i] = v.RuleName + "|" + v.Location
+	}
+
+	for i := 0; i < 25; i++ {
+		report, err := inspector.Inspect()
+		if err != nil {
+			t.Fatalf("Inspect() returned error on run %d: %v", i, err)
+		}
+
+		if len(report.Violations) != len(wantOrder) {
+			t.Fatalf("run %d: got %d violations, want %d", i, len(report.Violations), len(wantOrder))
+		}
+
+		for j, v := range report.Violations {
+			got := v.RuleName + "|" + v.Location
+			if got != wantOrder[j] {
+				t.Fatalf("run %d: violation[%d] = %q, want %q", i, j, got, wantOrder[j])
+			}
+		}
+	}
+}
+
 func TestInspectWithDisabledRules(t *testing.T) {
 	db := createTestDatabase()
 	config := GetDefaultConfig()

pkg/inspector/report.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"io"
 	"os"
+	"sort"
 	"strings"
 	"time"
 )
@@ -199,12 +200,18 @@ func (f *MarkdownFormatter) formatContext(context map[string]interface{}) string
 		"column": true,
 	}
 
-	for key, value := range context {
+	keys := make([]string, 0, len(context))
+	for key := range context {
+		keys = append(keys, key)
+	}
+	sort.Strings(keys)
+
+	for _, key := range keys {
 		if skipKeys[key] {
 			continue
 		}
 
-		parts = append(parts, fmt.Sprintf("%s=%v", key, value))
+		parts = append(parts, fmt.Sprintf("%s=%v", key, context[key]))
 	}
 
 	return strings.Join(parts, ", ")

pkg/inspector/validators.go

@@ -2,12 +2,54 @@ package inspector
 
 import (
 	"regexp"
+	"sort"
 	"strings"
 
 	"git.warky.dev/wdevs/relspecgo/pkg/models"
 	"git.warky.dev/wdevs/relspecgo/pkg/pgsql"
 )
 
+// sortedKeys returns a map's keys sorted alphabetically, so validators report
+// violations in a deterministic order instead of Go's randomized map order.
+func sortedKeys[T any](m map[string]T) []string {
+	keys := make([]string, 0, len(m))
+	for k := range m {
+		keys = append(keys, k)
+	}
+	sort.Strings(keys)
+	return keys
+}
+
+// sortColumns returns columns sorted by Sequence then Name for deterministic output.
+func sortColumns(columns map[string]*models.Column) []*models.Column {
+	result := make([]*models.Column, 0, len(columns))
+	for _, col := range columns {
+		result = append(result, col)
+	}
+	sort.Slice(result, func(i, j int) bool {
+		if result[i].Sequence > 0 && result[j].Sequence > 0 {
+			return result[i].Sequence < result[j].Sequence
+		}
+		return result[i].Name < result[j].Name
+	})
+	return result
+}
+
+// sortConstraints returns constraints sorted by Sequence then Name for deterministic output.
+func sortConstraints(constraints map[string]*models.Constraint) []*models.Constraint {
+	result := make([]*models.Constraint, 0, len(constraints))
+	for _, c := range constraints {
+		result = append(result, c)
+	}
+	sort.Slice(result, func(i, j int) bool {
+		if result[i].Sequence > 0 && result[j].Sequence > 0 {
+			return result[i].Sequence < result[j].Sequence
+		}
+		return result[i].Name < result[j].Name
+	})
+	return result
+}
+
 // validatePrimaryKeyNaming checks that primary key column names match a pattern
 func validatePrimaryKeyNaming(db *models.Database, rule Rule, ruleName string) []ValidationResult {
 	results := []ValidationResult{}
@@ -18,7 +60,7 @@ func validatePrimaryKeyNaming(db *models.Database, rule Rule, ruleName string) [
 
 	for _, schema := range db.Schemas {
 		for _, table := range schema.Tables {
-			for _, col := range table.Columns {
+			for _, col := range sortColumns(table.Columns) {
 				if col.IsPrimaryKey {
 					location := formatLocation(schema.Name, table.Name, col.Name)
 					passed := pattern.MatchString(col.Name)
@@ -49,7 +91,7 @@ func validatePrimaryKeyDatatype(db *models.Database, rule Rule, ruleName string)
 
 	for _, schema := range db.Schemas {
 		for _, table := range schema.Tables {
-			for _, col := range table.Columns {
+			for _, col := range sortColumns(table.Columns) {
 				if col.IsPrimaryKey {
 					location := formatLocation(schema.Name, table.Name, col.Name)
 
@@ -84,7 +126,7 @@ func validatePrimaryKeyAutoIncrement(db *models.Database, rule Rule, ruleName st
 
 	for _, schema := range db.Schemas {
 		for _, table := range schema.Tables {
-			for _, col := range table.Columns {
+			for _, col := range sortColumns(table.Columns) {
 				if col.IsPrimaryKey {
 					location := formatLocation(schema.Name, table.Name, col.Name)
 
@@ -125,7 +167,7 @@ func validateForeignKeyColumnNaming(db *models.Database, rule Rule, ruleName str
 	for _, schema := range db.Schemas {
 		for _, table := range schema.Tables {
 			// Check foreign key constraints
-			for _, constraint := range table.Constraints {
+			for _, constraint := range sortConstraints(table.Constraints) {
 				if constraint.Type == models.ForeignKeyConstraint {
 					for _, colName := range constraint.Columns {
 						location := formatLocation(schema.Name, table.Name, colName)
@@ -163,7 +205,7 @@ func validateForeignKeyConstraintNaming(db *models.Database, rule Rule, ruleName
 
 	for _, schema := range db.Schemas {
 		for _, table := range schema.Tables {
-			for _, constraint := range table.Constraints {
+			for _, constraint := range sortConstraints(table.Constraints) {
 				if constraint.Type == models.ForeignKeyConstraint {
 					location := formatLocation(schema.Name, table.Name, "")
 					passed := pattern.MatchString(constraint.Name)
@@ -209,7 +251,7 @@ func validateForeignKeyIndex(db *models.Database, rule Rule, ruleName string) []
 			}
 
 			// Check if each FK column has an index
-			for fkCol := range fkColumns {
+			for _, fkCol := range sortedKeys(fkColumns) {
 				hasIndex := false
 
 				// Check table indexes
@@ -282,7 +324,7 @@ func validateColumnNamingCase(db *models.Database, rule Rule, ruleName string) [
 
 	for _, schema := range db.Schemas {
 		for _, table := range schema.Tables {
-			for _, col := range table.Columns {
+			for _, col := range sortColumns(table.Columns) {
 				location := formatLocation(schema.Name, table.Name, col.Name)
 				passed := pattern.MatchString(col.Name)
 
@@ -339,7 +381,7 @@ func validateColumnNameLength(db *models.Database, rule Rule, ruleName string) [
 
 	for _, schema := range db.Schemas {
 		for _, table := range schema.Tables {
-			for _, col := range table.Columns {
+			for _, col := range sortColumns(table.Columns) {
 				location := formatLocation(schema.Name, table.Name, col.Name)
 				passed := len(col.Name) <= rule.MaxLength
 
@@ -396,7 +438,7 @@ func validateReservedKeywords(db *models.Database, rule Rule, ruleName string) [
 
 			// Check column names
 			if rule.CheckColumns {
-				for _, col := range table.Columns {
+				for _, col := range sortColumns(table.Columns) {
 					location := formatLocation(schema.Name, table.Name, col.Name)
 					passed := !keywords[strings.ToUpper(col.Name)]
 
@@ -479,7 +521,7 @@ func validateOrphanedForeignKey(db *models.Database, rule Rule, ruleName string)
 	// Check all foreign key constraints
 	for _, schema := range db.Schemas {
 		for _, table := range schema.Tables {
-			for _, constraint := range table.Constraints {
+			for _, constraint := range sortConstraints(table.Constraints) {
 				if constraint.Type == models.ForeignKeyConstraint {
 					// Build referenced table key
 					refSchema := constraint.ReferencedSchema
@@ -522,7 +564,7 @@ func validateCircularDependency(db *models.Database, rule Rule, ruleName string)
 		for _, table := range schema.Tables {
 			tableKey := schema.Name + "." + table.Name
 
-			for _, constraint := range table.Constraints {
+			for _, constraint := range sortConstraints(table.Constraints) {
 				if constraint.Type == models.ForeignKeyConstraint {
 					refSchema := constraint.ReferencedSchema
 					if refSchema == "" {
@@ -537,7 +579,7 @@ func validateCircularDependency(db *models.Database, rule Rule, ruleName string)
 	}
 
 	// Check for cycles using DFS
-	for tableKey := range dependencies {
+	for _, tableKey := range sortedKeys(dependencies) {
 		visited := make(map[string]bool)
 		recStack := make(map[string]bool)
 

pkg/merge/merge.go

@@ -5,6 +5,7 @@ package merge
 
 import (
 	"fmt"
+	"sort"
 	"strconv"
 	"strings"
 
@@ -156,8 +157,17 @@ func (r *MergeResult) mergeColumns(table *models.Table, srcTable *models.Table)
 		existingColumns[colName] = table.Columns[colName]
 	}
 
-	// Merge columns
-	for colName, srcCol := range srcTable.Columns {
+	// Merge columns in deterministic (alphabetical) order so that, when a
+	// TypeConflicts entry is recorded, its position in the report doesn't
+	// depend on Go's randomized map iteration order.
+	srcColNames := make([]string, 0, len(srcTable.Columns))
+	for colName := range srcTable.Columns {
+		srcColNames = append(srcColNames, colName)
+	}
+	sort.Strings(srcColNames)
+
+	for _, colName := range srcColNames {
+		srcCol := srcTable.Columns[colName]
 		if tgtCol, exists := existingColumns[colName]; !exists {
 			// Column doesn't exist, add it
 			newCol := cloneColumn(srcCol)

pkg/models/flatview.go

@@ -1,6 +1,9 @@
 package models
 
-import "fmt"
+import (
+	"fmt"
+	"sort"
+)
 
 // Flat/Denormalized Views
 //
@@ -56,6 +59,10 @@ func (d *Database) ToFlatColumns() []*FlatColumn {
 		}
 	}
 
+	sort.Slice(flatColumns, func(i, j int) bool {
+		return flatColumns[i].FullyQualifiedName < flatColumns[j].FullyQualifiedName
+	})
+
 	return flatColumns
 }
 
@@ -148,6 +155,10 @@ func (d *Database) ToFlatConstraints() []*FlatConstraint {
 		}
 	}
 
+	sort.Slice(flatConstraints, func(i, j int) bool {
+		return flatConstraints[i].FullyQualifiedName < flatConstraints[j].FullyQualifiedName
+	})
+
 	return flatConstraints
 }
 
@@ -198,5 +209,16 @@ func (d *Database) ToFlatRelationships() []*FlatRelationship {
 		}
 	}
 
+	sort.Slice(flatRelationships, func(i, j int) bool {
+		a, b := flatRelationships[i], flatRelationships[j]
+		if a.FromFQN != b.FromFQN {
+			return a.FromFQN < b.FromFQN
+		}
+		if a.RelationshipName != b.RelationshipName {
+			return a.RelationshipName < b.RelationshipName
+		}
+		return a.ToFQN < b.ToFQN
+	})
+
 	return flatRelationships
 }

pkg/models/models.go

@@ -5,6 +5,7 @@
 package models
 
 import (
+	"sort"
 	"strings"
 	"time"
 
@@ -141,15 +142,28 @@ func (d *Table) SQLName() string {
 
 // GetPrimaryKey returns the primary key column for the table, or nil if none exists.
 func (m Table) GetPrimaryKey() *Column {
+	var pk *Column
 	for _, column := range m.Columns {
-		if column.IsPrimaryKey {
-			return column
+		if !column.IsPrimaryKey {
+			continue
+		}
+		if pk == nil || columnLess(column, pk) {
+			pk = column
 		}
 	}
-	return nil
+	return pk
 }
 
-// GetForeignKeys returns all foreign key constraints for the table.
+// columnLess reports whether a should sort before b, by Sequence then Name.
+func columnLess(a, b *Column) bool {
+	if a.Sequence > 0 && b.Sequence > 0 {
+		return a.Sequence < b.Sequence
+	}
+	return a.Name < b.Name
+}
+
+// GetForeignKeys returns all foreign key constraints for the table, sorted
+// deterministically by Sequence then Name.
 func (m Table) GetForeignKeys() []*Constraint {
 	keys := make([]*Constraint, 0)
 
@@ -158,6 +172,12 @@ func (m Table) GetForeignKeys() []*Constraint {
 			keys = append(keys, c)
 		}
 	}
+	sort.Slice(keys, func(i, j int) bool {
+		if keys[i].Sequence > 0 && keys[j].Sequence > 0 {
+			return keys[i].Sequence < keys[j].Sequence
+		}
+		return keys[i].Name < keys[j].Name
+	})
 	return keys
 }
 

pkg/readers/dctx/reader.go

@@ -4,6 +4,7 @@ import (
 	"encoding/xml"
 	"fmt"
 	"os"
+	"sort"
 	"strings"
 
 	"git.warky.dev/wdevs/relspecgo/pkg/models"
@@ -373,7 +374,13 @@ func (r *Reader) convertKey(dctxKey *models.DCTXKey, table *models.Table, fieldG
 	if len(columns) == 0 {
 		if dctxKey.Primary {
 			// Look for common primary key column patterns
+			colNames := make([]string, 0, len(table.Columns))
 			for colName := range table.Columns {
+				colNames = append(colNames, colName)
+			}
+			sort.Strings(colNames)
+
+			for _, colName := range colNames {
 				colNameLower := strings.ToLower(colName)
 				if strings.HasPrefix(colNameLower, "rid_") || strings.HasSuffix(colNameLower, "id") {
 					columns = append(columns, colName)

pkg/readers/prisma/reader.go

@@ -820,17 +820,31 @@ func (r *Reader) createImplicitJoinTable(model1, model2 string, tableMap map[str
 	tableMap[joinTableName] = joinTable
 }
 
-// getPrimaryKeyColumn returns the primary key column of a table
+// getPrimaryKeyColumn returns the primary key column of a table. For tables
+// with a composite primary key, the column with the lowest Sequence (or,
+// failing that, the alphabetically first Name) is returned deterministically.
 func (r *Reader) getPrimaryKeyColumn(table *models.Table) *models.Column {
 	if table == nil {
 		return nil
 	}
 
+	var pk *models.Column
 	for _, col := range table.Columns {
-		if col.IsPrimaryKey {
-			return col
+		if !col.IsPrimaryKey {
+			continue
+		}
+		if pk == nil {
+			pk = col
+			continue
+		}
+		if col.Sequence > 0 && pk.Sequence > 0 {
+			if col.Sequence < pk.Sequence {
+				pk = col
+			}
+		} else if col.Name < pk.Name {
+			pk = col
 		}
 	}
 
-	return nil
+	return pk
 }

pkg/readers/typeorm/reader.go

@@ -806,17 +806,31 @@ func (r *Reader) createManyToManyJoinTable(entity1, entity2 string, tableMap map
 	tableMap[joinTableName] = joinTable
 }
 
-// getPrimaryKeyColumn returns the primary key column of a table
+// getPrimaryKeyColumn returns the primary key column of a table. For tables
+// with a composite primary key, the column with the lowest Sequence (or,
+// failing that, the alphabetically first Name) is returned deterministically.
 func (r *Reader) getPrimaryKeyColumn(table *models.Table) *models.Column {
 	if table == nil {
 		return nil
 	}
 
+	var pk *models.Column
 	for _, col := range table.Columns {
-		if col.IsPrimaryKey {
-			return col
+		if !col.IsPrimaryKey {
+			continue
+		}
+		if pk == nil {
+			pk = col
+			continue
+		}
+		if col.Sequence > 0 && pk.Sequence > 0 {
+			if col.Sequence < pk.Sequence {
+				pk = col
+			}
+		} else if col.Name < pk.Name {
+			pk = col
 		}
 	}
 
-	return nil
+	return pk
 }

pkg/ui/editor.go

@@ -2,6 +2,7 @@ package ui
 
 import (
 	"fmt"
+	"sort"
 
 	"github.com/rivo/tview"
 
@@ -69,5 +70,6 @@ func getColumnNames(table *models.Table) []string {
 	for name := range table.Columns {
 		names = append(names, name)
 	}
+	sort.Strings(names)
 	return names
 }

pkg/ui/relation_dataops.go

@@ -1,6 +1,10 @@
 package ui
 
-import "git.warky.dev/wdevs/relspecgo/pkg/models"
+import (
+	"sort"
+
+	"git.warky.dev/wdevs/relspecgo/pkg/models"
+)
 
 // Relationship data operations - business logic for relationship management
 
@@ -111,5 +115,6 @@ func (se *SchemaEditor) GetRelationshipNames(schemaIndex, tableIndex int) []stri
 	for name := range table.Relationships {
 		names = append(names, name)
 	}
+	sort.Strings(names)
 	return names
 }

pkg/writers/bun/template_data.go

@@ -220,8 +220,11 @@ func NewModelData(table *models.Table, schema string, typeMapper *TypeMapper, fl
 		Prefix:        GeneratePrefix(table.Name),
 	}
 
+	// Convert columns to fields (sorted by sequence or name)
+	columns := sortColumns(table.Columns)
+
 	// Find primary key
-	for _, col := range table.Columns {
+	for _, col := range columns {
 		if col.IsPrimaryKey {
 			// Sanitize column name to remove backticks
 			safeName := writers.SanitizeStructTagValue(col.Name)
@@ -240,8 +243,6 @@ func NewModelData(table *models.Table, schema string, typeMapper *TypeMapper, fl
 		}
 	}
 
-	// Convert columns to fields (sorted by sequence or name)
-	columns := sortColumns(table.Columns)
 	for _, col := range columns {
 		field := columnToField(col, table, typeMapper)
 		// Check for name collision with generated methods and rename if needed
@@ -335,6 +336,21 @@ func sortConstraints(constraints map[string]*models.Constraint) []*models.Constr
 	return result
 }
 
+// sortIndexes sorts indexes by sequence, then by name
+func sortIndexes(indexes map[string]*models.Index) []*models.Index {
+	result := make([]*models.Index, 0, len(indexes))
+	for _, idx := range indexes {
+		result = append(result, idx)
+	}
+	sort.Slice(result, func(i, j int) bool {
+		if result[i].Sequence > 0 && result[j].Sequence > 0 {
+			return result[i].Sequence < result[j].Sequence
+		}
+		return result[i].Name < result[j].Name
+	})
+	return result
+}
+
 // sortColumns sorts columns by sequence, then by name
 func sortColumns(columns map[string]*models.Column) []*models.Column {
 	result := make([]*models.Column, 0, len(columns))

pkg/writers/bun/type_mapper.go

@@ -383,7 +383,7 @@ func (tm *TypeMapper) BuildBunTag(column *models.Column, table *models.Table) st
 
 	// Check for indexes (unique indexes should be added to tag)
 	if table != nil {
-		for _, index := range table.Indexes {
+		for _, index := range sortIndexes(table.Indexes) {
 			if !index.Unique {
 				continue
 			}

pkg/writers/bun/writer_test.go

@@ -836,6 +836,43 @@ func TestTypeMapper_BuildBunTag(t *testing.T) {
 	}
 }
 
+// TestTypeMapper_BuildBunTag_MultipleUniqueIndexesDeterministic verifies that
+// when a column belongs to more than one unique index, the "unique:" tag
+// fragments always appear in the same order across repeated calls, instead
+// of following Go's randomized map iteration order over Table.Indexes.
+func TestTypeMapper_BuildBunTag_MultipleUniqueIndexesDeterministic(t *testing.T) {
+	mapper := NewTypeMapper("", "")
+	table := &models.Table{
+		Name: "accounts",
+		Indexes: map[string]*models.Index{
+			"idx_z_accounts_email_tenant": {
+				Name:    "idx_z_accounts_email_tenant",
+				Columns: []string{"email", "tenant_id"},
+				Unique:  true,
+			},
+			"idx_a_accounts_email_region": {
+				Name:    "idx_a_accounts_email_region",
+				Columns: []string{"email", "region_id"},
+				Unique:  true,
+			},
+		},
+	}
+	column := &models.Column{Name: "email", Type: "varchar", Length: 255, NotNull: true}
+
+	first := mapper.BuildBunTag(column, table)
+	for i := 0; i < 50; i++ {
+		got := mapper.BuildBunTag(column, table)
+		if got != first {
+			t.Fatalf("BuildBunTag() is non-deterministic across calls: %q vs %q", first, got)
+		}
+	}
+
+	wantOrder := "unique:idx_a_accounts_email_region,unique:idx_z_accounts_email_tenant,"
+	if !strings.Contains(first, wantOrder) {
+		t.Errorf("BuildBunTag() = %q, want unique tags sorted by index name: %q", first, wantOrder)
+	}
+}
+
 // TestTypeMapper_BuildBunTag_ArraysAreNativeInEveryMode verifies that array
 // columns always use a plain "text[]"-style type and the native Go slice
 // type plus an explicit "array" tag, regardless of NullableTypes style

pkg/writers/dbml/writer.go

@@ -3,6 +3,7 @@ package dbml
 import (
 	"fmt"
 	"os"
+	"sort"
 	"strings"
 
 	"git.warky.dev/wdevs/relspecgo/pkg/models"
@@ -78,7 +79,7 @@ func (w *Writer) databaseToDBML(d *models.Database) string {
 	sb.WriteString("\n// Relationships\n")
 	for _, schema := range d.Schemas {
 		for _, table := range schema.Tables {
-			for _, constraint := range table.Constraints {
+			for _, constraint := range sortConstraints(table.Constraints) {
 				if constraint.Type == models.ForeignKeyConstraint {
 					sb.WriteString(w.constraintToDBML(constraint, table))
 				}
@@ -112,7 +113,7 @@ func (w *Writer) tableToDBML(t *models.Table) string {
 	tableName := fmt.Sprintf("%s.%s", t.Schema, t.Name)
 	fmt.Fprintf(&sb, "Table %s {\n", tableName)
 
-	for _, column := range t.Columns {
+	for _, column := range sortColumns(t.Columns) {
 		fmt.Fprintf(&sb, "  %s %s", column.Name, column.Type)
 
 		var attrs []string
@@ -149,7 +150,7 @@ func (w *Writer) tableToDBML(t *models.Table) string {
 
 	if len(t.Indexes) > 0 {
 		sb.WriteString("\n  indexes {\n")
-		for _, index := range t.Indexes {
+		for _, index := range sortIndexes(t.Indexes) {
 			var indexAttrs []string
 			if index.Unique {
 				indexAttrs = append(indexAttrs, "unique")
@@ -230,3 +231,48 @@ func (w *Writer) constraintToDBML(c *models.Constraint, t *models.Table) string
 
 	return refLine + "\n"
 }
+
+// sortColumns returns columns sorted by Sequence then Name for deterministic output.
+func sortColumns(columns map[string]*models.Column) []*models.Column {
+	result := make([]*models.Column, 0, len(columns))
+	for _, col := range columns {
+		result = append(result, col)
+	}
+	sort.Slice(result, func(i, j int) bool {
+		if result[i].Sequence > 0 && result[j].Sequence > 0 {
+			return result[i].Sequence < result[j].Sequence
+		}
+		return result[i].Name < result[j].Name
+	})
+	return result
+}
+
+// sortConstraints returns constraints sorted by Sequence then Name for deterministic output.
+func sortConstraints(constraints map[string]*models.Constraint) []*models.Constraint {
+	result := make([]*models.Constraint, 0, len(constraints))
+	for _, c := range constraints {
+		result = append(result, c)
+	}
+	sort.Slice(result, func(i, j int) bool {
+		if result[i].Sequence > 0 && result[j].Sequence > 0 {
+			return result[i].Sequence < result[j].Sequence
+		}
+		return result[i].Name < result[j].Name
+	})
+	return result
+}
+
+// sortIndexes returns indexes sorted by Sequence then Name for deterministic output.
+func sortIndexes(indexes map[string]*models.Index) []*models.Index {
+	result := make([]*models.Index, 0, len(indexes))
+	for _, idx := range indexes {
+		result = append(result, idx)
+	}
+	sort.Slice(result, func(i, j int) bool {
+		if result[i].Sequence > 0 && result[j].Sequence > 0 {
+			return result[i].Sequence < result[j].Sequence
+		}
+		return result[i].Name < result[j].Name
+	})
+	return result
+}

pkg/writers/dctx/writer.go

@@ -66,7 +66,14 @@ func (w *Writer) WriteSchema(schema *models.Schema) error {
 
 	// Add table-level relationships
 	for _, table := range tableSlice {
-		for _, rel := range table.Relationships {
+		relNames := make([]string, 0, len(table.Relationships))
+		for name := range table.Relationships {
+			relNames = append(relNames, name)
+		}
+		sort.Strings(relNames)
+
+		for _, relName := range relNames {
+			rel := table.Relationships[relName]
 			// Check if this relationship is already in the list (avoid duplicates)
 			isDuplicate := false
 			for _, existing := range allRelations {

pkg/writers/drawdb/writer.go

@@ -4,6 +4,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"os"
+	"sort"
 
 	"git.warky.dev/wdevs/relspecgo/pkg/models"
 	"git.warky.dev/wdevs/relspecgo/pkg/writers"
@@ -175,7 +176,7 @@ func (w *Writer) databaseToDrawDB(d *models.Database) *DrawDBSchema {
 	// Add relationships
 	for _, schemaModel := range d.Schemas {
 		for _, table := range schemaModel.Tables {
-			for _, constraint := range table.Constraints {
+			for _, constraint := range sortConstraints(table.Constraints) {
 				if constraint.Type == models.ForeignKeyConstraint && constraint.ReferencedTable != "" {
 					startTableKey := fmt.Sprintf("%s.%s", schemaModel.Name, table.Name)
 					endTableKey := fmt.Sprintf("%s.%s", constraint.ReferencedSchema, constraint.ReferencedTable)
@@ -306,7 +307,7 @@ func (w *Writer) convertTableToDrawDB(table *models.Table, schemaName string, ta
 	}
 
 	// Add fields
-	for _, column := range table.Columns {
+	for _, column := range sortColumns(table.Columns) {
 		field := &DrawDBField{
 			ID:        fieldID,
 			Name:      column.Name,
@@ -339,7 +340,7 @@ func (w *Writer) convertTableToDrawDB(table *models.Table, schemaName string, ta
 
 	// Add indexes
 	indexID := 0
-	for _, index := range table.Indexes {
+	for _, index := range sortIndexes(table.Indexes) {
 		drawIndex := &DrawDBIndex{
 			ID:     indexID,
 			Name:   index.Name,
@@ -393,3 +394,48 @@ func getColorForIndex(index int) string {
 	}
 	return colors[index%len(colors)]
 }
+
+// sortColumns returns columns sorted by Sequence then Name for deterministic output.
+func sortColumns(columns map[string]*models.Column) []*models.Column {
+	result := make([]*models.Column, 0, len(columns))
+	for _, col := range columns {
+		result = append(result, col)
+	}
+	sort.Slice(result, func(i, j int) bool {
+		if result[i].Sequence > 0 && result[j].Sequence > 0 {
+			return result[i].Sequence < result[j].Sequence
+		}
+		return result[i].Name < result[j].Name
+	})
+	return result
+}
+
+// sortConstraints returns constraints sorted by Sequence then Name for deterministic output.
+func sortConstraints(constraints map[string]*models.Constraint) []*models.Constraint {
+	result := make([]*models.Constraint, 0, len(constraints))
+	for _, c := range constraints {
+		result = append(result, c)
+	}
+	sort.Slice(result, func(i, j int) bool {
+		if result[i].Sequence > 0 && result[j].Sequence > 0 {
+			return result[i].Sequence < result[j].Sequence
+		}
+		return result[i].Name < result[j].Name
+	})
+	return result
+}
+
+// sortIndexes returns indexes sorted by Sequence then Name for deterministic output.
+func sortIndexes(indexes map[string]*models.Index) []*models.Index {
+	result := make([]*models.Index, 0, len(indexes))
+	for _, idx := range indexes {
+		result = append(result, idx)
+	}
+	sort.Slice(result, func(i, j int) bool {
+		if result[i].Sequence > 0 && result[j].Sequence > 0 {
+			return result[i].Sequence < result[j].Sequence
+		}
+		return result[i].Name < result[j].Name
+	})
+	return result
+}

pkg/writers/drizzle/writer.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
+	"sort"
 	"strings"
 
 	"git.warky.dev/wdevs/relspecgo/pkg/models"
@@ -250,7 +251,7 @@ func (w *Writer) buildTableData(table *models.Table, schema *models.Schema, db *
 	indexColumnFields := make(map[string]bool)
 
 	// Add indexes (excluding single-column unique indexes, which are handled inline)
-	for _, index := range table.Indexes {
+	for _, index := range sortIndexes(table.Indexes) {
 		// Skip single-column unique indexes (handled by .unique() modifier)
 		if index.Unique && len(index.Columns) == 1 {
 			continue
@@ -270,7 +271,7 @@ func (w *Writer) buildTableData(table *models.Table, schema *models.Schema, db *
 	}
 
 	// Add multi-column unique constraints as unique indexes
-	for _, constraint := range table.Constraints {
+	for _, constraint := range sortConstraints(table.Constraints) {
 		if constraint.Type == models.UniqueConstraint && len(constraint.Columns) > 1 {
 			// Create a unique index for this constraint
 			indexData := &IndexData{
@@ -316,6 +317,36 @@ func (w *Writer) buildTableData(table *models.Table, schema *models.Schema, db *
 	return tableData
 }
 
+// sortIndexes returns indexes sorted by Sequence then Name for deterministic output.
+func sortIndexes(indexes map[string]*models.Index) []*models.Index {
+	result := make([]*models.Index, 0, len(indexes))
+	for _, idx := range indexes {
+		result = append(result, idx)
+	}
+	sort.Slice(result, func(i, j int) bool {
+		if result[i].Sequence > 0 && result[j].Sequence > 0 {
+			return result[i].Sequence < result[j].Sequence
+		}
+		return result[i].Name < result[j].Name
+	})
+	return result
+}
+
+// sortConstraints returns constraints sorted by Sequence then Name for deterministic output.
+func sortConstraints(constraints map[string]*models.Constraint) []*models.Constraint {
+	result := make([]*models.Constraint, 0, len(constraints))
+	for _, c := range constraints {
+		result = append(result, c)
+	}
+	sort.Slice(result, func(i, j int) bool {
+		if result[i].Sequence > 0 && result[j].Sequence > 0 {
+			return result[i].Sequence < result[j].Sequence
+		}
+		return result[i].Name < result[j].Name
+	})
+	return result
+}
+
 // sortStrings sorts a slice of strings in place
 func sortStrings(strs []string) {
 	for i := 0; i < len(strs); i++ {
@@ -422,7 +453,8 @@ func (w *Writer) getTableEnumNames(table *models.Table, schema *models.Schema, e
 	enumNames := make([]string, 0)
 	seen := make(map[string]bool)
 
-	for _, col := range table.Columns {
+	for _, colName := range w.getSortedColumnNames(table) {
+		col := table.Columns[colName]
 		if enumMap[col.Type] || enumMap[strings.ToLower(col.Type)] {
 			// Find the enum in schema
 			for _, enum := range schema.Enums {

pkg/writers/gorm/template_data.go

@@ -134,8 +134,11 @@ func NewModelData(table *models.Table, schema string, typeMapper *TypeMapper, fl
 		Prefix:        GeneratePrefix(table.Name),
 	}
 
+	// Convert columns to fields (sorted by sequence or name)
+	columns := sortColumns(table.Columns)
+
 	// Find primary key
-	for _, col := range table.Columns {
+	for _, col := range columns {
 		if col.IsPrimaryKey {
 			// Sanitize column name to remove backticks
 			safeName := writers.SanitizeStructTagValue(col.Name)
@@ -153,8 +156,6 @@ func NewModelData(table *models.Table, schema string, typeMapper *TypeMapper, fl
 		}
 	}
 
-	// Convert columns to fields (sorted by sequence or name)
-	columns := sortColumns(table.Columns)
 	for _, col := range columns {
 		field := columnToField(col, table, typeMapper)
 		// Check for name collision with generated methods and rename if needed
@@ -248,6 +249,21 @@ func sortConstraints(constraints map[string]*models.Constraint) []*models.Constr
 	return result
 }
 
+// sortIndexes sorts indexes by sequence, then by name
+func sortIndexes(indexes map[string]*models.Index) []*models.Index {
+	result := make([]*models.Index, 0, len(indexes))
+	for _, idx := range indexes {
+		result = append(result, idx)
+	}
+	sort.Slice(result, func(i, j int) bool {
+		if result[i].Sequence > 0 && result[j].Sequence > 0 {
+			return result[i].Sequence < result[j].Sequence
+		}
+		return result[i].Name < result[j].Name
+	})
+	return result
+}
+
 // sortColumns sorts columns by sequence, then by name
 func sortColumns(columns map[string]*models.Column) []*models.Column {
 	result := make([]*models.Column, 0, len(columns))

pkg/writers/gorm/type_mapper.go

@@ -415,7 +415,7 @@ func (tm *TypeMapper) BuildGormTag(column *models.Column, table *models.Table) s
 
 	// Check for unique constraint
 	if table != nil {
-		for _, constraint := range table.Constraints {
+		for _, constraint := range sortConstraints(table.Constraints) {
 			if constraint.Type == models.UniqueConstraint {
 				for _, col := range constraint.Columns {
 					if col == column.Name {
@@ -431,7 +431,7 @@ func (tm *TypeMapper) BuildGormTag(column *models.Column, table *models.Table) s
 		}
 
 		// Check for index
-		for _, index := range table.Indexes {
+		for _, index := range sortIndexes(table.Indexes) {
 			for _, col := range index.Columns {
 				if col == column.Name {
 					if index.Unique {

pkg/writers/gorm/writer_test.go

@@ -757,3 +757,48 @@ func TestTypeMapper_BuildGormTag_PreservesExplicitTypeModifiers(t *testing.T) {
 		t.Fatalf("type modifier appears duplicated in %q", tag)
 	}
 }
+
+// TestTypeMapper_BuildGormTag_MultipleUniqueIndexesDeterministic verifies
+// that when a column belongs to a unique constraint and more than one
+// unique index, the "uniqueIndex:" tag fragments always appear in the same
+// order across repeated calls, instead of following Go's randomized map
+// iteration order over Table.Constraints and Table.Indexes.
+func TestTypeMapper_BuildGormTag_MultipleUniqueIndexesDeterministic(t *testing.T) {
+	mapper := NewTypeMapper("")
+	table := &models.Table{
+		Name: "accounts",
+		Constraints: map[string]*models.Constraint{
+			"uq_z_accounts_email": {
+				Name:    "uq_z_accounts_email",
+				Type:    models.UniqueConstraint,
+				Columns: []string{"email"},
+			},
+		},
+		Indexes: map[string]*models.Index{
+			"idx_z_accounts_email_tenant": {
+				Name:    "idx_z_accounts_email_tenant",
+				Columns: []string{"email", "tenant_id"},
+				Unique:  true,
+			},
+			"idx_a_accounts_email_region": {
+				Name:    "idx_a_accounts_email_region",
+				Columns: []string{"email", "region_id"},
+				Unique:  true,
+			},
+		},
+	}
+	column := &models.Column{Name: "email", Type: "varchar", Length: 255, NotNull: true}
+
+	first := mapper.BuildGormTag(column, table)
+	for i := 0; i < 50; i++ {
+		got := mapper.BuildGormTag(column, table)
+		if got != first {
+			t.Fatalf("BuildGormTag() is non-deterministic across calls: %q vs %q", first, got)
+		}
+	}
+
+	wantOrder := "uniqueIndex:uq_z_accounts_email;uniqueIndex:idx_a_accounts_email_region;uniqueIndex:idx_z_accounts_email_tenant"
+	if !strings.Contains(first, wantOrder) {
+		t.Errorf("BuildGormTag() = %q, want uniqueIndex tags sorted (constraint before indexes, indexes by name): %q", first, wantOrder)
+	}
+}

pkg/writers/graphql/writer.go

@@ -233,7 +233,8 @@ func (w *Writer) tableToGraphQL(table *models.Table, db *models.Database, schema
 	// Add relation fields
 	relationFields = w.generateRelationFields(table, db, schema)
 
-	// Write fields in order: ID, scalars (sorted), relations (sorted)
+	// Write fields in order: ID (sorted), scalars (sorted), relations (sorted)
+	sort.Strings(idFields)
 	for _, field := range idFields {
 		sb.WriteString(field + "\n")
 	}

pkg/writers/pgsql/migration_writer.go

@@ -239,7 +239,8 @@ func (w *MigrationWriter) generateDropScripts(model *models.Schema, current *mod
 		}
 
 		// Check each constraint in current database
-		for constraintName, currentConstraint := range currentTable.Constraints {
+		for _, currentConstraint := range sortConstraints(currentTable.Constraints) {
+			constraintName := currentConstraint.Name
 			modelConstraint, existsInModel := modelTable.Constraints[constraintName]
 
 			shouldDrop := false
@@ -252,7 +253,8 @@ func (w *MigrationWriter) generateDropScripts(model *models.Schema, current *mod
 			if shouldDrop && currentConstraint.Type == models.PrimaryKeyConstraint {
 				// Drop FK constraints that depend on this PK before dropping the PK itself.
 				for _, otherTable := range current.Tables {
-					for fkName, fkConstraint := range otherTable.Constraints {
+					for _, fkConstraint := range sortConstraints(otherTable.Constraints) {
+						fkName := fkConstraint.Name
 						if fkConstraint.Type != models.ForeignKeyConstraint {
 							continue
 						}
@@ -310,7 +312,8 @@ func (w *MigrationWriter) generateDropScripts(model *models.Schema, current *mod
 		}
 
 		// Check indexes
-		for indexName, currentIndex := range currentTable.Indexes {
+		for _, currentIndex := range sortIndexes(currentTable.Indexes) {
+			indexName := currentIndex.Name
 			modelIndex, existsInModel := modelTable.Indexes[indexName]
 
 			shouldDrop := false
@@ -401,19 +404,12 @@ func (w *MigrationWriter) generateAlterTableScripts(schema *models.Schema, model
 	}
 
 	// Check each model column
-	for _, modelCol := range modelTable.Columns {
+	for _, modelCol := range sortColumns(modelTable.Columns) {
 		currentCol, exists := currentColumns[strings.ToLower(modelCol.Name)]
 
 		if !exists {
 			// Column doesn't exist, add it
-			defaultVal := ""
-			if modelCol.Default != nil {
-				if value, ok := modelCol.Default.(string); ok {
-					defaultVal = writers.QuoteDefaultValue(value, modelCol.Type)
-				} else {
-					defaultVal = fmt.Sprintf("%v", modelCol.Default)
-				}
-			}
+			_, defaultVal := formatColumnDefaultSQL(modelCol)
 
 			sql, err := w.executor.ExecuteAddColumn(AddColumnData{
 				SchemaName: schema.Name,
@@ -439,12 +435,14 @@ func (w *MigrationWriter) generateAlterTableScripts(schema *models.Schema, model
 		} else if !columnsEqual(modelCol, currentCol) {
 			// Column exists but properties changed
 			if !columnTypesEqual(modelCol, currentCol) {
-				sql, err := w.executor.ExecuteAlterColumnType(AlterColumnTypeData{
-					SchemaName: schema.Name,
-					TableName:  modelTable.Name,
-					ColumnName: modelCol.Name,
-					NewType:    effectiveAlterColumnSQLType(modelCol),
-					UsingExpr:  buildAlterColumnUsingExpression(modelCol.Name, effectiveAlterColumnSQLType(modelCol)),
+				newType := effectiveAlterColumnSQLType(modelCol)
+				sql, err := w.executor.ExecuteAlterColumnTypeWithCheck(AlterColumnTypeWithCheckData{
+					SchemaName:      schema.Name,
+					TableName:       modelTable.Name,
+					ColumnName:      modelCol.Name,
+					NewType:         newType,
+					EquivalentTypes: equivalentTypeListSQL(newType),
+					UsingExpr:       buildAlterColumnUsingExpression(modelCol.Name, newType),
 				})
 				if err != nil {
 					return nil, err
@@ -463,17 +461,9 @@ func (w *MigrationWriter) generateAlterTableScripts(schema *models.Schema, model
 
 			// Check default value changes
 			if fmt.Sprintf("%v", modelCol.Default) != fmt.Sprintf("%v", currentCol.Default) {
-				setDefault := modelCol.Default != nil
-				defaultVal := ""
-				if setDefault {
-					if value, ok := modelCol.Default.(string); ok {
-						defaultVal = writers.QuoteDefaultValue(value, modelCol.Type)
-					} else {
-						defaultVal = fmt.Sprintf("%v", modelCol.Default)
-					}
-				}
+				setDefault, defaultVal := formatColumnDefaultSQL(modelCol)
 
-				sql, err := w.executor.ExecuteAlterColumnDefault(AlterColumnDefaultData{
+				sql, err := w.executor.ExecuteAlterColumnDefaultWithCheck(AlterColumnDefaultWithCheckData{
 					SchemaName:   schema.Name,
 					TableName:    modelTable.Name,
 					ColumnName:   modelCol.Name,
@@ -494,6 +484,29 @@ func (w *MigrationWriter) generateAlterTableScripts(schema *models.Schema, model
 				}
 				scripts = append(scripts, script)
 			}
+
+			// Check nullability changes
+			if modelCol.NotNull != currentCol.NotNull {
+				sql, err := w.executor.ExecuteAlterColumnNullabilityWithCheck(AlterColumnNullabilityWithCheckData{
+					SchemaName: schema.Name,
+					TableName:  modelTable.Name,
+					ColumnName: modelCol.Name,
+					NotNull:    modelCol.NotNull,
+				})
+				if err != nil {
+					return nil, err
+				}
+
+				script := MigrationScript{
+					ObjectName: fmt.Sprintf("%s.%s.%s", schema.Name, modelTable.Name, modelCol.Name),
+					ObjectType: "alter column nullability",
+					Schema:     schema.Name,
+					Priority:   145,
+					Sequence:   len(scripts),
+					Body:       sql,
+				}
+				scripts = append(scripts, script)
+			}
 		}
 	}
 
@@ -518,7 +531,8 @@ func (w *MigrationWriter) generateIndexScripts(model *models.Schema, current *mo
 
 		// Process primary keys first - check explicit constraints
 		foundExplicitPK := false
-		for constraintName, constraint := range modelTable.Constraints {
+		for _, constraint := range sortConstraints(modelTable.Constraints) {
+			constraintName := constraint.Name
 			if constraint.Type == models.PrimaryKeyConstraint {
 				foundExplicitPK = true
 				shouldCreate := true
@@ -603,7 +617,8 @@ func (w *MigrationWriter) generateIndexScripts(model *models.Schema, current *mo
 		}
 
 		// Process indexes
-		for indexName, modelIndex := range modelTable.Indexes {
+		for _, modelIndex := range sortIndexes(modelTable.Indexes) {
+			indexName := modelIndex.Name
 			// Skip primary key indexes
 			if strings.HasPrefix(strings.ToLower(indexName), "pk_") {
 				continue
@@ -697,7 +712,8 @@ func (w *MigrationWriter) generateForeignKeyScripts(model *models.Schema, curren
 		currentTable := currentTables[strings.ToLower(modelTable.Name)]
 
 		// Process each constraint
-		for constraintName, constraint := range modelTable.Constraints {
+		for _, constraint := range sortConstraints(modelTable.Constraints) {
+			constraintName := constraint.Name
 			if constraint.Type != models.ForeignKeyConstraint {
 				continue
 			}
@@ -787,7 +803,7 @@ func (w *MigrationWriter) generateCommentScripts(model *models.Schema, current *
 		}
 
 		// Column comments
-		for _, col := range modelTable.Columns {
+		for _, col := range sortColumns(modelTable.Columns) {
 			if col.Description != "" {
 				sql, err := w.executor.ExecuteCommentColumn(CommentColumnData{
 					SchemaName: model.Name,

pkg/writers/pgsql/migration_writer_test.go

@@ -136,6 +136,89 @@ func TestWriteMigration_AltersColumnTypeWhenActualTypeDiffers(t *testing.T) {
 	}
 }
 
+func TestWriteMigration_AltersColumnTypeFallsBackToRenameAndAddOnConversionFailure(t *testing.T) {
+	current := models.InitDatabase("testdb")
+	currentSchema := models.InitSchema("public")
+	currentTable := models.InitTable("learnings", "public")
+	currentDetails := models.InitColumn("details", "learnings", "public")
+	currentDetails.Type = "varchar(50)"
+	currentTable.Columns["details"] = currentDetails
+	currentSchema.Tables = append(currentSchema.Tables, currentTable)
+	current.Schemas = append(current.Schemas, currentSchema)
+
+	model := models.InitDatabase("testdb")
+	modelSchema := models.InitSchema("public")
+	modelTable := models.InitTable("learnings", "public")
+	modelDetails := models.InitColumn("details", "learnings", "public")
+	modelDetails.Type = "integer"
+	modelTable.Columns["details"] = modelDetails
+	modelSchema.Tables = append(modelSchema.Tables, modelTable)
+	model.Schemas = append(model.Schemas, modelSchema)
+
+	var buf bytes.Buffer
+	writer, err := NewMigrationWriter(&writers.WriterOptions{})
+	if err != nil {
+		t.Fatalf("Failed to create writer: %v", err)
+	}
+	writer.writer = &buf
+
+	if err := writer.WriteMigration(model, current); err != nil {
+		t.Fatalf("WriteMigration failed: %v", err)
+	}
+
+	output := buf.String()
+	if !strings.Contains(output, "EXCEPTION WHEN OTHERS THEN") {
+		t.Fatalf("expected migration to guard the type conversion with an exception handler, got:\n%s", output)
+	}
+	if !strings.Contains(output, "RENAME COLUMN details TO %I") {
+		t.Fatalf("expected migration to rename the old column (derived from the live type) on conversion failure, got:\n%s", output)
+	}
+	if !strings.Contains(output, "renamed_column := 'details_' || trim(both '_' from regexp_replace(lower(current_type)") {
+		t.Fatalf("expected migration to derive the renamed column name from the live type, got:\n%s", output)
+	}
+	if !strings.Contains(output, "ADD COLUMN details integer") {
+		t.Fatalf("expected migration to add a fresh column with the new type on conversion failure, got:\n%s", output)
+	}
+}
+
+func TestWriteMigration_AltersColumnNullabilityWhenNotNullDiffers(t *testing.T) {
+	current := models.InitDatabase("testdb")
+	currentSchema := models.InitSchema("public")
+	currentTable := models.InitTable("service_instance", "public")
+	currentType := models.InitColumn("rid_service_instance_type", "service_instance", "public")
+	currentType.Type = "text"
+	currentType.NotNull = true
+	currentTable.Columns["rid_service_instance_type"] = currentType
+	currentSchema.Tables = append(currentSchema.Tables, currentTable)
+	current.Schemas = append(current.Schemas, currentSchema)
+
+	model := models.InitDatabase("testdb")
+	modelSchema := models.InitSchema("public")
+	modelTable := models.InitTable("service_instance", "public")
+	modelType := models.InitColumn("rid_service_instance_type", "service_instance", "public")
+	modelType.Type = "text"
+	modelType.NotNull = false
+	modelTable.Columns["rid_service_instance_type"] = modelType
+	modelSchema.Tables = append(modelSchema.Tables, modelTable)
+	model.Schemas = append(model.Schemas, modelSchema)
+
+	var buf bytes.Buffer
+	writer, err := NewMigrationWriter(&writers.WriterOptions{})
+	if err != nil {
+		t.Fatalf("Failed to create writer: %v", err)
+	}
+	writer.writer = &buf
+
+	if err := writer.WriteMigration(model, current); err != nil {
+		t.Fatalf("WriteMigration failed: %v", err)
+	}
+
+	output := buf.String()
+	if !strings.Contains(output, "ALTER COLUMN rid_service_instance_type DROP NOT NULL") {
+		t.Fatalf("expected migration to drop NOT NULL on existing column, got:\n%s", output)
+	}
+}
+
 func TestWriteMigration_UsesStorageTypeForSerialAlterStatements(t *testing.T) {
 	current := models.InitDatabase("testdb")
 	currentSchema := models.InitSchema("public")

pkg/writers/pgsql/templates.go

@@ -89,15 +89,10 @@ type AddColumnData struct {
 	NotNull    bool
 }
 
-// AlterColumnTypeData contains data for alter column type template
-type AlterColumnTypeData struct {
-	SchemaName string
-	TableName  string
-	ColumnName string
-	NewType    string
-	UsingExpr  string
-}
-
+// AlterColumnTypeWithCheckData contains data for the guarded alter column
+// type template, which only alters existing columns whose live type
+// differs from the desired one, and falls back to renaming the old column
+// and adding a fresh one when the in-place conversion is not possible.
 type AlterColumnTypeWithCheckData struct {
 	SchemaName      string
 	TableName       string
@@ -107,8 +102,10 @@ type AlterColumnTypeWithCheckData struct {
 	UsingExpr       string
 }
 
-// AlterColumnDefaultData contains data for alter column default template
-type AlterColumnDefaultData struct {
+// AlterColumnDefaultWithCheckData contains data for the guarded alter
+// column default template, which only alters existing columns whose live
+// default differs from the desired one.
+type AlterColumnDefaultWithCheckData struct {
 	SchemaName   string
 	TableName    string
 	ColumnName   string
@@ -116,6 +113,16 @@ type AlterColumnDefaultData struct {
 	DefaultValue string
 }
 
+// AlterColumnNullabilityWithCheckData contains data for the guarded alter
+// column nullability template, which only alters existing columns whose
+// live NOT NULL state differs from the desired one.
+type AlterColumnNullabilityWithCheckData struct {
+	SchemaName string
+	TableName  string
+	ColumnName string
+	NotNull    bool
+}
+
 // CreatePrimaryKeyData contains data for create primary key template
 type CreatePrimaryKeyData struct {
 	SchemaName     string
@@ -302,16 +309,9 @@ func (te *TemplateExecutor) ExecuteAddColumn(data AddColumnData) (string, error)
 	return buf.String(), nil
 }
 
-// ExecuteAlterColumnType executes the alter column type template
-func (te *TemplateExecutor) ExecuteAlterColumnType(data AlterColumnTypeData) (string, error) {
-	var buf bytes.Buffer
-	err := te.templates.ExecuteTemplate(&buf, "alter_column_type.tmpl", data)
-	if err != nil {
-		return "", fmt.Errorf("failed to execute alter_column_type template: %w", err)
-	}
-	return buf.String(), nil
-}
-
+// ExecuteAlterColumnTypeWithCheck executes the guarded alter column type
+// template shared by the full-schema writer and the diff-based migration
+// writer.
 func (te *TemplateExecutor) ExecuteAlterColumnTypeWithCheck(data AlterColumnTypeWithCheckData) (string, error) {
 	var buf bytes.Buffer
 	err := te.templates.ExecuteTemplate(&buf, "alter_column_type_with_check.tmpl", data)
@@ -321,12 +321,25 @@ func (te *TemplateExecutor) ExecuteAlterColumnTypeWithCheck(data AlterColumnType
 	return buf.String(), nil
 }
 
-// ExecuteAlterColumnDefault executes the alter column default template
-func (te *TemplateExecutor) ExecuteAlterColumnDefault(data AlterColumnDefaultData) (string, error) {
+// ExecuteAlterColumnDefaultWithCheck executes the guarded alter column
+// default template shared by the full-schema writer and the diff-based
+// migration writer.
+func (te *TemplateExecutor) ExecuteAlterColumnDefaultWithCheck(data AlterColumnDefaultWithCheckData) (string, error) {
 	var buf bytes.Buffer
-	err := te.templates.ExecuteTemplate(&buf, "alter_column_default.tmpl", data)
+	err := te.templates.ExecuteTemplate(&buf, "alter_column_default_with_check.tmpl", data)
 	if err != nil {
-		return "", fmt.Errorf("failed to execute alter_column_default template: %w", err)
+		return "", fmt.Errorf("failed to execute alter_column_default_with_check template: %w", err)
+	}
+	return buf.String(), nil
+}
+
+// ExecuteAlterColumnNullabilityWithCheck executes the guarded alter column
+// nullability template.
+func (te *TemplateExecutor) ExecuteAlterColumnNullabilityWithCheck(data AlterColumnNullabilityWithCheckData) (string, error) {
+	var buf bytes.Buffer
+	err := te.templates.ExecuteTemplate(&buf, "alter_column_nullability_with_check.tmpl", data)
+	if err != nil {
+		return "", fmt.Errorf("failed to execute alter_column_nullability_with_check template: %w", err)
 	}
 	return buf.String(), nil
 }
@@ -545,7 +558,7 @@ func BuildAuditFunctionData(
 
 	// Build list of audited columns
 	auditedColumns := make([]*models.Column, 0)
-	for _, col := range table.Columns {
+	for _, col := range sortColumns(table.Columns) {
 		if col.Name == pk.Name {
 			continue
 		}

pkg/writers/pgsql/templates/alter_column_default.tmpl

@@ -1,7 +0,0 @@
-{{- if .SetDefault -}}
-ALTER TABLE {{qual_table .SchemaName .TableName}}
-  ALTER COLUMN {{quote_ident .ColumnName}} SET DEFAULT {{.DefaultValue}};
-{{- else -}}
-ALTER TABLE {{qual_table .SchemaName .TableName}}
-  ALTER COLUMN {{quote_ident .ColumnName}} DROP DEFAULT;
-{{- end -}}

pkg/writers/pgsql/templates/alter_column_default_with_check.tmpl

@@ -0,0 +1,29 @@
+DO $$
+DECLARE
+  current_default text;
+BEGIN
+  SELECT pg_catalog.pg_get_expr(d.adbin, d.adrelid)
+    INTO current_default
+  FROM pg_attribute a
+  JOIN pg_class t ON t.oid = a.attrelid
+  JOIN pg_namespace n ON n.oid = t.relnamespace
+  LEFT JOIN pg_attrdef d ON d.adrelid = a.attrelid AND d.adnum = a.attnum
+  WHERE n.nspname = '{{.SchemaName}}'
+    AND t.relname = '{{.TableName}}'
+    AND a.attname = '{{.ColumnName}}'
+    AND a.attnum > 0
+    AND NOT a.attisdropped;
+
+{{- if .SetDefault }}
+  IF current_default IS DISTINCT FROM {{quote .DefaultValue}} THEN
+    ALTER TABLE {{qual_table .SchemaName .TableName}}
+      ALTER COLUMN {{quote_ident .ColumnName}} SET DEFAULT {{.DefaultValue}};
+  END IF;
+{{- else }}
+  IF current_default IS NOT NULL THEN
+    ALTER TABLE {{qual_table .SchemaName .TableName}}
+      ALTER COLUMN {{quote_ident .ColumnName}} DROP DEFAULT;
+  END IF;
+{{- end }}
+END;
+$$;

pkg/writers/pgsql/templates/alter_column_nullability_with_check.tmpl

@@ -0,0 +1,26 @@
+DO $$
+DECLARE
+  current_not_null boolean;
+BEGIN
+  SELECT a.attnotnull
+    INTO current_not_null
+  FROM pg_attribute a
+  JOIN pg_class t ON t.oid = a.attrelid
+  JOIN pg_namespace n ON n.oid = t.relnamespace
+  WHERE n.nspname = '{{.SchemaName}}'
+    AND t.relname = '{{.TableName}}'
+    AND a.attname = '{{.ColumnName}}'
+    AND a.attnum > 0
+    AND NOT a.attisdropped;
+
+  IF current_not_null IS NOT NULL AND current_not_null IS DISTINCT FROM {{.NotNull}} THEN
+{{- if .NotNull }}
+    ALTER TABLE {{qual_table .SchemaName .TableName}}
+      ALTER COLUMN {{quote_ident .ColumnName}} SET NOT NULL;
+{{- else }}
+    ALTER TABLE {{qual_table .SchemaName .TableName}}
+      ALTER COLUMN {{quote_ident .ColumnName}} DROP NOT NULL;
+{{- end }}
+  END IF;
+END;
+$$;

pkg/writers/pgsql/templates/alter_column_type.tmpl

@@ -1,2 +0,0 @@
-ALTER TABLE {{qual_table .SchemaName .TableName}}
-  ALTER COLUMN {{quote_ident .ColumnName}} TYPE {{.NewType}}{{if .UsingExpr}} USING {{.UsingExpr}}{{end}};

pkg/writers/pgsql/templates/alter_column_type_with_check.tmpl

@@ -1,6 +1,7 @@
 DO $$
 DECLARE
   current_type text;
+  renamed_column text;
 BEGIN
   SELECT pg_catalog.format_type(a.atttypid, a.atttypmod)
     INTO current_type
@@ -15,8 +16,15 @@ BEGIN
 
   IF current_type IS NOT NULL
      AND current_type <> ALL(ARRAY[{{.EquivalentTypes}}]) THEN
-    ALTER TABLE {{qual_table .SchemaName .TableName}}
-      ALTER COLUMN {{quote_ident .ColumnName}} TYPE {{.NewType}}{{if .UsingExpr}} USING {{.UsingExpr}}{{end}};
+    BEGIN
+      ALTER TABLE {{qual_table .SchemaName .TableName}}
+        ALTER COLUMN {{quote_ident .ColumnName}} TYPE {{.NewType}}{{if .UsingExpr}} USING {{.UsingExpr}}{{end}};
+    EXCEPTION WHEN OTHERS THEN
+      renamed_column := '{{.ColumnName}}_' || trim(both '_' from regexp_replace(lower(current_type), '[^a-z0-9]+', '_', 'g'));
+      EXECUTE format('ALTER TABLE {{qual_table .SchemaName .TableName}} RENAME COLUMN {{quote_ident .ColumnName}} TO %I', renamed_column);
+      ALTER TABLE {{qual_table .SchemaName .TableName}}
+        ADD COLUMN {{quote_ident .ColumnName}} {{.NewType}};
+    END;
   END IF;
 END;
 $$;

pkg/writers/pgsql/writer.go

@@ -199,7 +199,7 @@ func (w *Writer) GenerateSchemaStatements(schema *models.Schema) ([]string, erro
 	for _, table := range schema.Tables {
 		// First check for explicit PrimaryKeyConstraint
 		var pkConstraint *models.Constraint
-		for _, constraint := range table.Constraints {
+		for _, constraint := range sortConstraints(table.Constraints) {
 			if constraint.Type == models.PrimaryKeyConstraint {
 				pkConstraint = constraint
 				break
@@ -255,7 +255,7 @@ func (w *Writer) GenerateSchemaStatements(schema *models.Schema) ([]string, erro
 
 	// Phase 5: Indexes
 	for _, table := range schema.Tables {
-		for _, index := range table.Indexes {
+		for _, index := range sortIndexes(table.Indexes) {
 			// Skip primary key indexes
 			if strings.HasSuffix(index.Name, "_pkey") {
 				continue
@@ -298,7 +298,7 @@ func (w *Writer) GenerateSchemaStatements(schema *models.Schema) ([]string, erro
 
 	// Phase 5.5: Unique constraints
 	for _, table := range schema.Tables {
-		for _, constraint := range table.Constraints {
+		for _, constraint := range sortConstraints(table.Constraints) {
 			if constraint.Type != models.UniqueConstraint {
 				continue
 			}
@@ -321,7 +321,7 @@ func (w *Writer) GenerateSchemaStatements(schema *models.Schema) ([]string, erro
 
 	// Phase 5.7: Check constraints
 	for _, table := range schema.Tables {
-		for _, constraint := range table.Constraints {
+		for _, constraint := range sortConstraints(table.Constraints) {
 			if constraint.Type != models.CheckConstraint {
 				continue
 			}
@@ -344,7 +344,7 @@ func (w *Writer) GenerateSchemaStatements(schema *models.Schema) ([]string, erro
 
 	// Phase 6: Foreign keys
 	for _, table := range schema.Tables {
-		for _, constraint := range table.Constraints {
+		for _, constraint := range sortConstraints(table.Constraints) {
 			if constraint.Type != models.ForeignKeyConstraint {
 				continue
 			}
@@ -394,7 +394,7 @@ func (w *Writer) GenerateSchemaStatements(schema *models.Schema) ([]string, erro
 			statements = append(statements, stmt)
 		}
 
-		for _, column := range table.Columns {
+		for _, column := range sortColumns(table.Columns) {
 			if column.Comment != "" {
 				stmt := fmt.Sprintf("COMMENT ON COLUMN %s.%s IS '%s'",
 					w.qualTable(schema.SQLName(), table.SQLName()), column.SQLName(), escapeQuote(column.Comment))
@@ -475,6 +475,75 @@ func (w *Writer) GenerateAlterColumnTypeStatements(schema *models.Schema) ([]str
 	return statements, nil
 }
 
+// GenerateAlterColumnDefaultStatements generates guarded ALTER TABLE
+// statements to bring existing columns' DEFAULT clause in line with the
+// model, safe to run against a database that already has the columns.
+func (w *Writer) GenerateAlterColumnDefaultStatements(schema *models.Schema) ([]string, error) {
+	statements := []string{}
+
+	statements = append(statements, fmt.Sprintf("-- Alter column defaults for schema: %s", schema.Name))
+
+	for _, table := range schema.Tables {
+		columns := getSortedColumns(table.Columns)
+		for _, col := range columns {
+			setDefault, defaultVal := formatColumnDefaultSQL(col)
+			stmt, err := w.executor.ExecuteAlterColumnDefaultWithCheck(AlterColumnDefaultWithCheckData{
+				SchemaName:   schema.Name,
+				TableName:    table.Name,
+				ColumnName:   col.Name,
+				SetDefault:   setDefault,
+				DefaultValue: defaultVal,
+			})
+			if err != nil {
+				return nil, fmt.Errorf("failed to generate alter column default for %s.%s.%s: %w", schema.Name, table.Name, col.Name, err)
+			}
+			statements = append(statements, stmt)
+		}
+	}
+
+	return statements, nil
+}
+
+// formatColumnDefaultSQL renders a column's model-level default into the
+// SQL literal/expression used by ALTER COLUMN ... SET DEFAULT, shared by
+// the full-schema writer and the diff-based migration writer.
+func formatColumnDefaultSQL(col *models.Column) (setDefault bool, defaultVal string) {
+	if col.Default == nil {
+		return false, ""
+	}
+	if value, ok := col.Default.(string); ok {
+		return true, writers.QuoteDefaultValue(value, col.Type)
+	}
+	return true, fmt.Sprintf("%v", col.Default)
+}
+
+// GenerateAlterColumnNullabilityStatements generates guarded ALTER TABLE
+// statements to bring existing columns' NOT NULL state in line with the
+// model, safe to run against a database that already has the columns.
+func (w *Writer) GenerateAlterColumnNullabilityStatements(schema *models.Schema) ([]string, error) {
+	statements := []string{}
+
+	statements = append(statements, fmt.Sprintf("-- Alter column nullability for schema: %s", schema.Name))
+
+	for _, table := range schema.Tables {
+		columns := getSortedColumns(table.Columns)
+		for _, col := range columns {
+			stmt, err := w.executor.ExecuteAlterColumnNullabilityWithCheck(AlterColumnNullabilityWithCheckData{
+				SchemaName: schema.Name,
+				TableName:  table.Name,
+				ColumnName: col.Name,
+				NotNull:    col.NotNull,
+			})
+			if err != nil {
+				return nil, fmt.Errorf("failed to generate alter column nullability for %s.%s.%s: %w", schema.Name, table.Name, col.Name, err)
+			}
+			statements = append(statements, stmt)
+		}
+	}
+
+	return statements, nil
+}
+
 // GenerateAddColumnsForDatabase generates ALTER TABLE ADD COLUMN statements for the entire database
 func (w *Writer) GenerateAddColumnsForDatabase(db *models.Database) ([]string, error) {
 	statements := []string{}
@@ -641,6 +710,14 @@ func (w *Writer) WriteSchema(schema *models.Schema) error {
 		return err
 	}
 
+	if err := w.writeAlterColumnDefaults(schema); err != nil {
+		return err
+	}
+
+	if err := w.writeAlterColumnNullability(schema); err != nil {
+		return err
+	}
+
 	// Phase 4: Create primary keys (priority 160)
 	if err := w.writePrimaryKeys(schema); err != nil {
 		return err
@@ -859,6 +936,36 @@ func (w *Writer) writeAlterColumnTypes(schema *models.Schema) error {
 	return nil
 }
 
+func (w *Writer) writeAlterColumnDefaults(schema *models.Schema) error {
+	fmt.Fprintf(w.writer, "-- Alter column defaults for schema: %s\n", schema.Name)
+
+	statements, err := w.GenerateAlterColumnDefaultStatements(schema)
+	if err != nil {
+		return err
+	}
+	for _, stmt := range statements[1:] {
+		fmt.Fprint(w.writer, stmt)
+		fmt.Fprint(w.writer, "\n")
+	}
+
+	return nil
+}
+
+func (w *Writer) writeAlterColumnNullability(schema *models.Schema) error {
+	fmt.Fprintf(w.writer, "-- Alter column nullability for schema: %s\n", schema.Name)
+
+	statements, err := w.GenerateAlterColumnNullabilityStatements(schema)
+	if err != nil {
+		return err
+	}
+	for _, stmt := range statements[1:] {
+		fmt.Fprint(w.writer, stmt)
+		fmt.Fprint(w.writer, "\n")
+	}
+
+	return nil
+}
+
 // writePrimaryKeys generates ALTER TABLE statements for primary keys
 func (w *Writer) writePrimaryKeys(schema *models.Schema) error {
 	fmt.Fprintf(w.writer, "-- Primary keys for schema: %s\n", schema.Name)
@@ -866,10 +973,9 @@ func (w *Writer) writePrimaryKeys(schema *models.Schema) error {
 	for _, table := range schema.Tables {
 		// Find primary key constraint
 		var pkConstraint *models.Constraint
-		for name, constraint := range table.Constraints {
+		for _, constraint := range sortConstraints(table.Constraints) {
 			if constraint.Type == models.PrimaryKeyConstraint {
 				pkConstraint = constraint
-				_ = name // Use the name variable
 				break
 			}
 		}
@@ -1475,6 +1581,51 @@ func resolveIndexColumn(table *models.Table, colName string) (*models.Column, bo
 	return nil, false
 }
 
+// sortColumns returns columns sorted by Sequence then Name for deterministic output.
+func sortColumns(columns map[string]*models.Column) []*models.Column {
+	result := make([]*models.Column, 0, len(columns))
+	for _, col := range columns {
+		result = append(result, col)
+	}
+	sort.Slice(result, func(i, j int) bool {
+		if result[i].Sequence > 0 && result[j].Sequence > 0 {
+			return result[i].Sequence < result[j].Sequence
+		}
+		return result[i].Name < result[j].Name
+	})
+	return result
+}
+
+// sortConstraints returns constraints sorted by Sequence then Name for deterministic output.
+func sortConstraints(constraints map[string]*models.Constraint) []*models.Constraint {
+	result := make([]*models.Constraint, 0, len(constraints))
+	for _, c := range constraints {
+		result = append(result, c)
+	}
+	sort.Slice(result, func(i, j int) bool {
+		if result[i].Sequence > 0 && result[j].Sequence > 0 {
+			return result[i].Sequence < result[j].Sequence
+		}
+		return result[i].Name < result[j].Name
+	})
+	return result
+}
+
+// sortIndexes returns indexes sorted by Sequence then Name for deterministic output.
+func sortIndexes(indexes map[string]*models.Index) []*models.Index {
+	result := make([]*models.Index, 0, len(indexes))
+	for _, idx := range indexes {
+		result = append(result, idx)
+	}
+	sort.Slice(result, func(i, j int) bool {
+		if result[i].Sequence > 0 && result[j].Sequence > 0 {
+			return result[i].Sequence < result[j].Sequence
+		}
+		return result[i].Name < result[j].Name
+	})
+	return result
+}
+
 // formatStringList formats a list of strings as a SQL-safe comma-separated quoted list
 func formatStringList(items []string) string {
 	quoted := make([]string, len(items))

pkg/writers/pgsql/writer_test.go

@@ -1106,6 +1106,113 @@ func TestWriteSchema_EmitsGuardedAlterColumnTypeStatements(t *testing.T) {
 	}
 }
 
+func TestWriteSchema_EmitsGuardedAlterColumnDefaultStatements(t *testing.T) {
+	db := models.InitDatabase("testdb")
+	schema := models.InitSchema("public")
+
+	table := models.InitTable("agent_skills", "public")
+
+	statusCol := models.InitColumn("status", "agent_skills", "public")
+	statusCol.Type = "text"
+	statusCol.Default = "active"
+	table.Columns["status"] = statusCol
+
+	schema.Tables = append(schema.Tables, table)
+	db.Schemas = append(db.Schemas, schema)
+
+	var buf bytes.Buffer
+	writer := NewWriter(&writers.WriterOptions{})
+	writer.writer = &buf
+
+	if err := writer.WriteDatabase(db); err != nil {
+		t.Fatalf("WriteDatabase failed: %v", err)
+	}
+
+	output := buf.String()
+	if !strings.Contains(output, "-- Alter column defaults for schema: public") {
+		t.Fatalf("expected alter column default section, got:\n%s", output)
+	}
+	if !strings.Contains(output, "pg_get_expr(d.adbin, d.adrelid)") {
+		t.Fatalf("expected guarded live-default check, got:\n%s", output)
+	}
+	if !strings.Contains(output, "ALTER COLUMN status SET DEFAULT 'active'") {
+		t.Fatalf("expected guarded SET DEFAULT for status column, got:\n%s", output)
+	}
+}
+
+func TestWriteSchema_GuardedAlterColumnTypeFallsBackOnConversionFailure(t *testing.T) {
+	db := models.InitDatabase("testdb")
+	schema := models.InitSchema("public")
+
+	table := models.InitTable("agent_skills", "public")
+
+	nameCol := models.InitColumn("name", "agent_skills", "public")
+	nameCol.Type = "integer"
+	table.Columns["name"] = nameCol
+
+	schema.Tables = append(schema.Tables, table)
+	db.Schemas = append(db.Schemas, schema)
+
+	var buf bytes.Buffer
+	writer := NewWriter(&writers.WriterOptions{})
+	writer.writer = &buf
+
+	if err := writer.WriteDatabase(db); err != nil {
+		t.Fatalf("WriteDatabase failed: %v", err)
+	}
+
+	output := buf.String()
+	if !strings.Contains(output, "EXCEPTION WHEN OTHERS THEN") {
+		t.Fatalf("expected guarded alter to fall back on conversion failure, got:\n%s", output)
+	}
+	if !strings.Contains(output, "renamed_column := 'name_' || trim(both '_' from regexp_replace(lower(current_type)") {
+		t.Fatalf("expected fallback to derive a renamed column name from the live type, got:\n%s", output)
+	}
+	if !strings.Contains(output, "RENAME COLUMN name TO %I") {
+		t.Fatalf("expected fallback to rename the existing column, got:\n%s", output)
+	}
+	if !strings.Contains(output, "ADD COLUMN name integer") {
+		t.Fatalf("expected fallback to add a fresh column with the new type, got:\n%s", output)
+	}
+}
+
+func TestWriteSchema_EmitsGuardedAlterColumnNullabilityStatements(t *testing.T) {
+	db := models.InitDatabase("testdb")
+	schema := models.InitSchema("origin")
+
+	table := models.InitTable("service_instance", "origin")
+
+	typeCol := models.InitColumn("rid_service_instance_type", "service_instance", "origin")
+	typeCol.Type = "text"
+	typeCol.NotNull = false
+	table.Columns["rid_service_instance_type"] = typeCol
+
+	schema.Tables = append(schema.Tables, table)
+	db.Schemas = append(db.Schemas, schema)
+
+	var buf bytes.Buffer
+	writer := NewWriter(&writers.WriterOptions{})
+	writer.writer = &buf
+
+	if err := writer.WriteDatabase(db); err != nil {
+		t.Fatalf("WriteDatabase failed: %v", err)
+	}
+
+	output := buf.String()
+	if !strings.Contains(output, "-- Alter column nullability for schema: origin") {
+		t.Fatalf("expected alter column nullability section, got:\n%s", output)
+	}
+	if !strings.Contains(output, "a.attnotnull") {
+		t.Fatalf("expected guarded live-nullability check, got:\n%s", output)
+	}
+	if !strings.Contains(output, "current_not_null IS DISTINCT FROM false") {
+		t.Fatalf("expected guard comparing live nullability against desired value, got:\n%s", output)
+	}
+	if !strings.Contains(output, "ALTER COLUMN rid_service_instance_type DROP NOT NULL") {
+		t.Fatalf("expected guarded DROP NOT NULL for nullable column, got:\n%s", output)
+	}
+}
+
 func TestWriteSchema_UsesStorageTypeForSerialAlterStatements(t *testing.T) {
 	db := models.InitDatabase("testdb")
 	schema := models.InitSchema("public")

pkg/writers/prisma/writer.go

@@ -549,14 +549,14 @@ func (w *Writer) generateBlockAttributes(table *models.Table) string {
 	}
 
 	// @@unique for multi-column unique constraints
-	for _, constraint := range table.Constraints {
+	for _, constraint := range sortConstraints(table.Constraints) {
 		if constraint.Type == models.UniqueConstraint && len(constraint.Columns) > 1 {
 			fmt.Fprintf(&sb, "  @@unique([%s])\n", strings.Join(constraint.Columns, ", "))
 		}
 	}
 
 	// @@index for indexes
-	for _, index := range table.Indexes {
+	for _, index := range sortIndexes(table.Indexes) {
 		if !index.Unique { // Unique indexes are handled by @@unique
 			fmt.Fprintf(&sb, "  @@index([%s])\n", strings.Join(index.Columns, ", "))
 		}
@@ -564,3 +564,33 @@ func (w *Writer) generateBlockAttributes(table *models.Table) string {
 
 	return sb.String()
 }
+
+// sortConstraints returns constraints sorted by Sequence then Name for deterministic output.
+func sortConstraints(constraints map[string]*models.Constraint) []*models.Constraint {
+	result := make([]*models.Constraint, 0, len(constraints))
+	for _, c := range constraints {
+		result = append(result, c)
+	}
+	sort.Slice(result, func(i, j int) bool {
+		if result[i].Sequence > 0 && result[j].Sequence > 0 {
+			return result[i].Sequence < result[j].Sequence
+		}
+		return result[i].Name < result[j].Name
+	})
+	return result
+}
+
+// sortIndexes returns indexes sorted by Sequence then Name for deterministic output.
+func sortIndexes(indexes map[string]*models.Index) []*models.Index {
+	result := make([]*models.Index, 0, len(indexes))
+	for _, idx := range indexes {
+		result = append(result, idx)
+	}
+	sort.Slice(result, func(i, j int) bool {
+		if result[i].Sequence > 0 && result[j].Sequence > 0 {
+			return result[i].Sequence < result[j].Sequence
+		}
+		return result[i].Name < result[j].Name
+	})
+	return result
+}

pkg/writers/sqlite/templates.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"embed"
 	"fmt"
+	"sort"
 	"text/template"
 
 	"git.warky.dev/wdevs/relspecgo/pkg/models"
@@ -133,15 +134,11 @@ func (te *TemplateExecutor) ExecuteCreateForeignKey(data ConstraintTemplateData)
 
 // BuildTableTemplateData builds TableTemplateData from a models.Table
 func BuildTableTemplateData(schema string, table *models.Table) TableTemplateData {
-	// Get sorted columns
-	columns := make([]*models.Column, 0, len(table.Columns))
-	for _, col := range table.Columns {
-		columns = append(columns, col)
-	}
+	columns := sortColumns(table.Columns)
 
 	// Find primary key constraint
 	var pk *models.Constraint
-	for _, constraint := range table.Constraints {
+	for _, constraint := range sortConstraints(table.Constraints) {
 		if constraint.Type == models.PrimaryKeyConstraint {
 			pk = constraint
 			break
@@ -151,7 +148,7 @@ func BuildTableTemplateData(schema string, table *models.Table) TableTemplateDat
 	// If no explicit primary key constraint, build one from columns with IsPrimaryKey=true
 	if pk == nil {
 		pkCols := []string{}
-		for _, col := range table.Columns {
+		for _, col := range columns {
 			if col.IsPrimaryKey {
 				pkCols = append(pkCols, col.Name)
 			}
@@ -172,3 +169,48 @@ func BuildTableTemplateData(schema string, table *models.Table) TableTemplateDat
 		PrimaryKey: pk,
 	}
 }
+
+// sortColumns returns columns sorted by Sequence then Name for deterministic output.
+func sortColumns(columns map[string]*models.Column) []*models.Column {
+	result := make([]*models.Column, 0, len(columns))
+	for _, col := range columns {
+		result = append(result, col)
+	}
+	sort.Slice(result, func(i, j int) bool {
+		if result[i].Sequence > 0 && result[j].Sequence > 0 {
+			return result[i].Sequence < result[j].Sequence
+		}
+		return result[i].Name < result[j].Name
+	})
+	return result
+}
+
+// sortConstraints returns constraints sorted by Sequence then Name for deterministic output.
+func sortConstraints(constraints map[string]*models.Constraint) []*models.Constraint {
+	result := make([]*models.Constraint, 0, len(constraints))
+	for _, c := range constraints {
+		result = append(result, c)
+	}
+	sort.Slice(result, func(i, j int) bool {
+		if result[i].Sequence > 0 && result[j].Sequence > 0 {
+			return result[i].Sequence < result[j].Sequence
+		}
+		return result[i].Name < result[j].Name
+	})
+	return result
+}
+
+// sortIndexes returns indexes sorted by Sequence then Name for deterministic output.
+func sortIndexes(indexes map[string]*models.Index) []*models.Index {
+	result := make([]*models.Index, 0, len(indexes))
+	for _, idx := range indexes {
+		result = append(result, idx)
+	}
+	sort.Slice(result, func(i, j int) bool {
+		if result[i].Sequence > 0 && result[j].Sequence > 0 {
+			return result[i].Sequence < result[j].Sequence
+		}
+		return result[i].Name < result[j].Name
+	})
+	return result
+}

pkg/writers/sqlite/writer.go

@@ -143,7 +143,7 @@ func (w *Writer) writeTable(schema string, table *models.Table) error {
 
 // writeIndexes writes indexes for a table
 func (w *Writer) writeIndexes(schema string, table *models.Table) error {
-	for _, index := range table.Indexes {
+	for _, index := range sortIndexes(table.Indexes) {
 		// Skip primary key indexes
 		if strings.HasSuffix(index.Name, "_pkey") {
 			continue
@@ -174,7 +174,7 @@ func (w *Writer) writeIndexes(schema string, table *models.Table) error {
 
 // writeUniqueConstraints writes unique constraints as unique indexes
 func (w *Writer) writeUniqueConstraints(schema string, table *models.Table) error {
-	for _, constraint := range table.Constraints {
+	for _, constraint := range sortConstraints(table.Constraints) {
 		if constraint.Type != models.UniqueConstraint {
 			continue
 		}
@@ -195,7 +195,7 @@ func (w *Writer) writeUniqueConstraints(schema string, table *models.Table) erro
 	}
 
 	// Also handle unique indexes from the Indexes map
-	for _, index := range table.Indexes {
+	for _, index := range sortIndexes(table.Indexes) {
 		if !index.Unique {
 			continue
 		}
@@ -232,7 +232,7 @@ func (w *Writer) writeUniqueConstraints(schema string, table *models.Table) erro
 
 // writeCheckConstraints writes check constraints as comments
 func (w *Writer) writeCheckConstraints(schema string, table *models.Table) error {
-	for _, constraint := range table.Constraints {
+	for _, constraint := range sortConstraints(table.Constraints) {
 		if constraint.Type != models.CheckConstraint {
 			continue
 		}
@@ -257,7 +257,7 @@ func (w *Writer) writeCheckConstraints(schema string, table *models.Table) error
 
 // writeForeignKeys writes foreign keys as comments
 func (w *Writer) writeForeignKeys(schema string, table *models.Table) error {
-	for _, constraint := range table.Constraints {
+	for _, constraint := range sortConstraints(table.Constraints) {
 		if constraint.Type != models.ForeignKeyConstraint {
 			continue
 		}

pkg/writers/typeorm/writer.go

@@ -531,7 +531,13 @@ func (w *Writer) generateInverseRelations(table *models.Table, schema *models.Sc
 
 // generateManyToManyRelations generates @ManyToMany fields
 func (w *Writer) generateManyToManyRelations(table *models.Table, schema *models.Schema, joinTables map[string]bool, sb *strings.Builder) {
-	for joinTableName := range joinTables {
+	joinTableNames := make([]string, 0, len(joinTables))
+	for name := range joinTables {
+		joinTableNames = append(joinTableNames, name)
+	}
+	sort.Strings(joinTableNames)
+
+	for _, joinTableName := range joinTableNames {
 		joinTable := w.findTable(joinTableName, schema)
 		if joinTable == nil {
 			continue