feat(writer): 🎉 Add support for unique constraints in schema generation

* Implement unique constraint handling in GenerateSchemaStatements
* Add writeUniqueConstraints method for generating SQL statements
* Create unit test for unique constraints in writer_test.go

cmd/relspec/scripts.go

@@ -14,10 +14,11 @@ import (
 )
 
 var (
-	scriptsDir        string
+	scriptsDir          string
-	scriptsConn       string
+	scriptsConn         string
-	scriptsSchemaName string
+	scriptsSchemaName   string
-	scriptsDBName     string
+	scriptsDBName       string
+	scriptsIgnoreErrors bool
 )
 
 var scriptsCmd = &cobra.Command{
@@ -62,7 +63,7 @@ var scriptsExecuteCmd = &cobra.Command{
 	Long: `Execute SQL scripts from a directory against a PostgreSQL database.
 
 Scripts are executed in order: Priority (ascending), Sequence (ascending), Name (alphabetical).
-Execution stops immediately on the first error.
+By default, execution stops immediately on the first error. Use --ignore-errors to continue execution.
 
 The directory is scanned recursively for all subdirectories and files matching the patterns:
   {priority}_{sequence}_{name}.sql or .pgsql (underscore format)
@@ -86,7 +87,12 @@ Examples:
 
   # Execute with SSL disabled
   relspec scripts execute --dir ./sql \
-                          --conn "postgres://user:pass@localhost/db?sslmode=disable"`,
+                          --conn "postgres://user:pass@localhost/db?sslmode=disable"
+
+  # Continue executing even if errors occur
+  relspec scripts execute --dir ./migrations \
+                          --conn "postgres://localhost/mydb" \
+                          --ignore-errors`,
 	RunE: runScriptsExecute,
 }
 
@@ -105,6 +111,7 @@ func init() {
 	scriptsExecuteCmd.Flags().StringVar(&scriptsConn, "conn", "", "PostgreSQL connection string (required)")
 	scriptsExecuteCmd.Flags().StringVar(&scriptsSchemaName, "schema", "public", "Schema name (optional, default: public)")
 	scriptsExecuteCmd.Flags().StringVar(&scriptsDBName, "database", "database", "Database name (optional, default: database)")
+	scriptsExecuteCmd.Flags().BoolVar(&scriptsIgnoreErrors, "ignore-errors", false, "Continue executing scripts even if errors occur")
 
 	err = scriptsExecuteCmd.MarkFlagRequired("dir")
 	if err != nil {
@@ -250,17 +257,39 @@ func runScriptsExecute(cmd *cobra.Command, args []string) error {
 	writer := sqlexec.NewWriter(&writers.WriterOptions{
 		Metadata: map[string]any{
 			"connection_string": scriptsConn,
+			"ignore_errors":     scriptsIgnoreErrors,
 		},
 	})
 
 	if err := writer.WriteSchema(schema); err != nil {
 		fmt.Fprintf(os.Stderr, "\n")
-		return fmt.Errorf("execution failed: %w", err)
+		return fmt.Errorf("script execution failed: %w", err)
+	}
+
+	// Get execution results from writer metadata
+	totalCount := len(schema.Scripts)
+	successCount := totalCount
+	failedCount := 0
+
+	opts := writer.Options()
+	if total, exists := opts.Metadata["execution_total"].(int); exists {
+		totalCount = total
+	}
+	if success, exists := opts.Metadata["execution_success"].(int); exists {
+		successCount = success
+	}
+	if failed, exists := opts.Metadata["execution_failed"].(int); exists {
+		failedCount = failed
 	}
 
 	fmt.Fprintf(os.Stderr, "\n=== Execution Complete ===\n")
 	fmt.Fprintf(os.Stderr, "Completed at: %s\n", getCurrentTimestamp())
-	fmt.Fprintf(os.Stderr, "Successfully executed %d script(s)\n\n", len(schema.Scripts))
+	fmt.Fprintf(os.Stderr, "Total scripts: %d\n", totalCount)
+	fmt.Fprintf(os.Stderr, "Successful:    %d\n", successCount)
+	if failedCount > 0 {
+		fmt.Fprintf(os.Stderr, "Failed:        %d\n", failedCount)
+	}
+	fmt.Fprintf(os.Stderr, "\n")
 
 	return nil
 }

pkg/readers/dbml/reader.go

@@ -128,6 +128,46 @@ func (r *Reader) readDirectoryDBML(dirPath string) (*models.Database, error) {
 	return db, nil
 }
 
+// splitIdentifier splits a dotted identifier while respecting quotes
+// Handles cases like: "schema.with.dots"."table"."column"
+func splitIdentifier(s string) []string {
+	var parts []string
+	var current strings.Builder
+	inQuote := false
+	quoteChar := byte(0)
+
+	for i := 0; i < len(s); i++ {
+		ch := s[i]
+
+		if !inQuote {
+			switch ch {
+			case '"', '\'':
+				inQuote = true
+				quoteChar = ch
+				current.WriteByte(ch)
+			case '.':
+				if current.Len() > 0 {
+					parts = append(parts, current.String())
+					current.Reset()
+				}
+			default:
+				current.WriteByte(ch)
+			}
+		} else {
+			current.WriteByte(ch)
+			if ch == quoteChar {
+				inQuote = false
+			}
+		}
+	}
+
+	if current.Len() > 0 {
+		parts = append(parts, current.String())
+	}
+
+	return parts
+}
+
 // stripQuotes removes surrounding quotes and comments from an identifier
 func stripQuotes(s string) string {
 	s = strings.TrimSpace(s)
@@ -409,7 +449,9 @@ func (r *Reader) parseDBML(content string) (*models.Database, error) {
 		// Parse Table definition
 		if matches := tableRegex.FindStringSubmatch(line); matches != nil {
 			tableName := matches[1]
-			parts := strings.Split(tableName, ".")
+			// Strip comments/notes before parsing to avoid dots in notes
+			tableName = strings.TrimSpace(regexp.MustCompile(`\s*\[.*?\]\s*`).ReplaceAllString(tableName, ""))
+			parts := splitIdentifier(tableName)
 
 			if len(parts) == 2 {
 				currentSchema = stripQuotes(parts[0])
@@ -814,7 +856,7 @@ func (r *Reader) parseTableRef(ref string) (schema, table string, columns []stri
 	}
 
 	// Parse schema, table, and optionally column
-	parts := strings.Split(strings.TrimSpace(ref), ".")
+	parts := splitIdentifier(strings.TrimSpace(ref))
 	if len(parts) == 3 {
 		// Format: "schema"."table"."column"
 		schema = stripQuotes(parts[0])

pkg/writers/pgsql/writer.go

@@ -168,6 +168,13 @@ func (w *Writer) GenerateSchemaStatements(schema *models.Schema) ([]string, erro
 		statements = append(statements, stmts...)
 	}
 
+	// Phase 3.5: Add missing columns (for existing tables)
+	addColStmts, err := w.GenerateAddColumnStatements(schema)
+	if err != nil {
+		return nil, fmt.Errorf("failed to generate add column statements: %w", err)
+	}
+	statements = append(statements, addColStmts...)
+
 	// Phase 4: Primary keys
 	for _, table := range schema.Tables {
 		// First check for explicit PrimaryKeyConstraint
@@ -288,6 +295,31 @@ func (w *Writer) GenerateSchemaStatements(schema *models.Schema) ([]string, erro
 		}
 	}
 
+	// Phase 5.5: Unique constraints
+	for _, table := range schema.Tables {
+		for _, constraint := range table.Constraints {
+			if constraint.Type != models.UniqueConstraint {
+				continue
+			}
+
+			// Wrap in DO block to check for existing constraint
+			stmt := fmt.Sprintf("DO $$\nBEGIN\n"+
+				"  IF NOT EXISTS (\n"+
+				"    SELECT 1 FROM information_schema.table_constraints\n"+
+				"    WHERE table_schema = '%s'\n"+
+				"      AND table_name = '%s'\n"+
+				"      AND constraint_name = '%s'\n"+
+				"  ) THEN\n"+
+				"    ALTER TABLE %s.%s ADD CONSTRAINT %s UNIQUE (%s);\n"+
+				"  END IF;\n"+
+				"END;\n$$",
+				schema.Name, table.Name, constraint.Name,
+				schema.SQLName(), table.SQLName(), constraint.Name,
+				strings.Join(constraint.Columns, ", "))
+			statements = append(statements, stmt)
+		}
+	}
+
 	// Phase 6: Foreign keys
 	for _, table := range schema.Tables {
 		for _, constraint := range table.Constraints {
@@ -351,6 +383,68 @@ func (w *Writer) GenerateSchemaStatements(schema *models.Schema) ([]string, erro
 	return statements, nil
 }
 
+// GenerateAddColumnStatements generates ALTER TABLE ADD COLUMN statements for existing tables
+// This is useful for schema evolution when new columns are added to existing tables
+func (w *Writer) GenerateAddColumnStatements(schema *models.Schema) ([]string, error) {
+	statements := []string{}
+
+	statements = append(statements, fmt.Sprintf("-- Add missing columns for schema: %s", schema.Name))
+
+	for _, table := range schema.Tables {
+		// Sort columns by sequence or name for consistent output
+		columns := make([]*models.Column, 0, len(table.Columns))
+		for _, col := range table.Columns {
+			columns = append(columns, col)
+		}
+		sort.Slice(columns, func(i, j int) bool {
+			if columns[i].Sequence != columns[j].Sequence {
+				return columns[i].Sequence < columns[j].Sequence
+			}
+			return columns[i].Name < columns[j].Name
+		})
+
+		for _, col := range columns {
+			colDef := w.generateColumnDefinition(col)
+
+			// Generate DO block that checks if column exists before adding
+			stmt := fmt.Sprintf("DO $$\nBEGIN\n"+
+				"  IF NOT EXISTS (\n"+
+				"    SELECT 1 FROM information_schema.columns\n"+
+				"    WHERE table_schema = '%s'\n"+
+				"      AND table_name = '%s'\n"+
+				"      AND column_name = '%s'\n"+
+				"  ) THEN\n"+
+				"    ALTER TABLE %s.%s ADD COLUMN %s;\n"+
+				"  END IF;\n"+
+				"END;\n$$",
+				schema.Name, table.Name, col.Name,
+				schema.SQLName(), table.SQLName(), colDef)
+			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{}
+
+	statements = append(statements, "-- Add missing columns to existing tables")
+	statements = append(statements, fmt.Sprintf("-- Database: %s", db.Name))
+	statements = append(statements, "-- Generated by RelSpec")
+
+	for _, schema := range db.Schemas {
+		schemaStatements, err := w.GenerateAddColumnStatements(schema)
+		if err != nil {
+			return nil, fmt.Errorf("failed to generate add column statements for schema %s: %w", schema.Name, err)
+		}
+		statements = append(statements, schemaStatements...)
+	}
+
+	return statements, nil
+}
+
 // generateCreateTableStatement generates CREATE TABLE statement
 func (w *Writer) generateCreateTableStatement(schema *models.Schema, table *models.Table) ([]string, error) {
 	statements := []string{}
@@ -373,7 +467,7 @@ func (w *Writer) generateCreateTableStatement(schema *models.Schema, table *mode
 		columnDefs = append(columnDefs, "  "+def)
 	}
 
-	stmt := fmt.Sprintf("CREATE TABLE %s.%s (\n%s\n)",
+	stmt := fmt.Sprintf("CREATE TABLE IF NOT EXISTS %s.%s (\n%s\n)",
 		schema.SQLName(), table.SQLName(), strings.Join(columnDefs, ",\n"))
 	statements = append(statements, stmt)
 
@@ -458,6 +552,11 @@ func (w *Writer) WriteSchema(schema *models.Schema) error {
 		return err
 	}
 
+	// Phase 3.5: Add missing columns (priority 120)
+	if err := w.writeAddColumns(schema); err != nil {
+		return err
+	}
+
 	// Phase 4: Create primary keys (priority 160)
 	if err := w.writePrimaryKeys(schema); err != nil {
 		return err
@@ -468,6 +567,11 @@ func (w *Writer) WriteSchema(schema *models.Schema) error {
 		return err
 	}
 
+	// Phase 5.5: Create unique constraints (priority 185)
+	if err := w.writeUniqueConstraints(schema); err != nil {
+		return err
+	}
+
 	// Phase 6: Create foreign key constraints (priority 195)
 	if err := w.writeForeignKeys(schema); err != nil {
 		return err
@@ -499,6 +603,44 @@ func (w *Writer) WriteTable(table *models.Table) error {
 	return w.WriteSchema(schema)
 }
 
+// WriteAddColumnStatements writes ALTER TABLE ADD COLUMN statements for a database
+// This is used for schema evolution/migration when new columns are added
+func (w *Writer) WriteAddColumnStatements(db *models.Database) error {
+	var writer io.Writer
+	var file *os.File
+	var err error
+
+	// Use existing writer if already set (for testing)
+	if w.writer != nil {
+		writer = w.writer
+	} else if w.options.OutputPath != "" {
+		// Determine output destination
+		file, err = os.Create(w.options.OutputPath)
+		if err != nil {
+			return fmt.Errorf("failed to create output file: %w", err)
+		}
+		defer file.Close()
+		writer = file
+	} else {
+		writer = os.Stdout
+	}
+
+	w.writer = writer
+
+	// Generate statements
+	statements, err := w.GenerateAddColumnsForDatabase(db)
+	if err != nil {
+		return err
+	}
+
+	// Write each statement
+	for _, stmt := range statements {
+		fmt.Fprintf(w.writer, "%s;\n\n", stmt)
+	}
+
+	return nil
+}
+
 // writeCreateSchema generates CREATE SCHEMA statement
 func (w *Writer) writeCreateSchema(schema *models.Schema) error {
 	if schema.Name == "public" {
@@ -564,6 +706,35 @@ func (w *Writer) writeCreateTables(schema *models.Schema) error {
 	return nil
 }
 
+// writeAddColumns generates ALTER TABLE ADD COLUMN statements for missing columns
+func (w *Writer) writeAddColumns(schema *models.Schema) error {
+	fmt.Fprintf(w.writer, "-- Add missing columns for schema: %s\n", schema.Name)
+
+	for _, table := range schema.Tables {
+		// Sort columns by sequence or name for consistent output
+		columns := getSortedColumns(table.Columns)
+
+		for _, col := range columns {
+			colDef := w.generateColumnDefinition(col)
+
+			// Generate DO block that checks if column exists before adding
+			fmt.Fprintf(w.writer, "DO $$\nBEGIN\n")
+			fmt.Fprintf(w.writer, "  IF NOT EXISTS (\n")
+			fmt.Fprintf(w.writer, "    SELECT 1 FROM information_schema.columns\n")
+			fmt.Fprintf(w.writer, "    WHERE table_schema = '%s'\n", schema.Name)
+			fmt.Fprintf(w.writer, "      AND table_name = '%s'\n", table.Name)
+			fmt.Fprintf(w.writer, "      AND column_name = '%s'\n", col.Name)
+			fmt.Fprintf(w.writer, "  ) THEN\n")
+			fmt.Fprintf(w.writer, "    ALTER TABLE %s.%s ADD COLUMN %s;\n",
+				schema.SQLName(), table.SQLName(), colDef)
+			fmt.Fprintf(w.writer, "  END IF;\n")
+			fmt.Fprintf(w.writer, "END;\n$$;\n\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)
@@ -724,6 +895,55 @@ func (w *Writer) writeIndexes(schema *models.Schema) error {
 	return nil
 }
 
+// writeUniqueConstraints generates ALTER TABLE statements for unique constraints
+func (w *Writer) writeUniqueConstraints(schema *models.Schema) error {
+	fmt.Fprintf(w.writer, "-- Unique constraints for schema: %s\n", schema.Name)
+
+	for _, table := range schema.Tables {
+		// Sort constraints by name for consistent output
+		constraintNames := make([]string, 0, len(table.Constraints))
+		for name, constraint := range table.Constraints {
+			if constraint.Type == models.UniqueConstraint {
+				constraintNames = append(constraintNames, name)
+			}
+		}
+		sort.Strings(constraintNames)
+
+		for _, name := range constraintNames {
+			constraint := table.Constraints[name]
+
+			// Build column list
+			columnExprs := make([]string, 0, len(constraint.Columns))
+			for _, colName := range constraint.Columns {
+				if col, ok := table.Columns[colName]; ok {
+					columnExprs = append(columnExprs, col.SQLName())
+				}
+			}
+
+			if len(columnExprs) == 0 {
+				continue
+			}
+
+			// Wrap in DO block to check for existing constraint
+			fmt.Fprintf(w.writer, "DO $$\n")
+			fmt.Fprintf(w.writer, "BEGIN\n")
+			fmt.Fprintf(w.writer, "  IF NOT EXISTS (\n")
+			fmt.Fprintf(w.writer, "    SELECT 1 FROM information_schema.table_constraints\n")
+			fmt.Fprintf(w.writer, "    WHERE table_schema = '%s'\n", schema.Name)
+			fmt.Fprintf(w.writer, "      AND table_name = '%s'\n", table.Name)
+			fmt.Fprintf(w.writer, "      AND constraint_name = '%s'\n", constraint.Name)
+			fmt.Fprintf(w.writer, "  ) THEN\n")
+			fmt.Fprintf(w.writer, "    ALTER TABLE %s.%s ADD CONSTRAINT %s UNIQUE (%s);\n",
+				schema.SQLName(), table.SQLName(), constraint.Name, strings.Join(columnExprs, ", "))
+			fmt.Fprintf(w.writer, "  END IF;\n")
+			fmt.Fprintf(w.writer, "END;\n")
+			fmt.Fprintf(w.writer, "$$;\n\n")
+		}
+	}
+
+	return nil
+}
+
 // writeForeignKeys generates ALTER TABLE statements for foreign keys
 func (w *Writer) writeForeignKeys(schema *models.Schema) error {
 	fmt.Fprintf(w.writer, "-- Foreign keys for schema: %s\n", schema.Name)

pkg/writers/pgsql/writer_test.go

@@ -164,6 +164,76 @@ func TestWriteForeignKeys(t *testing.T) {
 	}
 }
 
+func TestWriteUniqueConstraints(t *testing.T) {
+	// Create a test database with unique constraints
+	db := models.InitDatabase("testdb")
+	schema := models.InitSchema("public")
+
+	// Create table with unique constraints
+	table := models.InitTable("users", "public")
+
+	// Add columns
+	emailCol := models.InitColumn("email", "users", "public")
+	emailCol.Type = "varchar(255)"
+	emailCol.NotNull = true
+	table.Columns["email"] = emailCol
+
+	guidCol := models.InitColumn("guid", "users", "public")
+	guidCol.Type = "uuid"
+	guidCol.NotNull = true
+	table.Columns["guid"] = guidCol
+
+	// Add unique constraints
+	emailConstraint := &models.Constraint{
+		Name:    "uq_email",
+		Type:    models.UniqueConstraint,
+		Schema:  "public",
+		Table:   "users",
+		Columns: []string{"email"},
+	}
+	table.Constraints["uq_email"] = emailConstraint
+
+	guidConstraint := &models.Constraint{
+		Name:    "uq_guid",
+		Type:    models.UniqueConstraint,
+		Schema:  "public",
+		Table:   "users",
+		Columns: []string{"guid"},
+	}
+	table.Constraints["uq_guid"] = guidConstraint
+
+	schema.Tables = append(schema.Tables, table)
+	db.Schemas = append(db.Schemas, schema)
+
+	// Create writer with output to buffer
+	var buf bytes.Buffer
+	options := &writers.WriterOptions{}
+	writer := NewWriter(options)
+	writer.writer = &buf
+
+	// Write the database
+	err := writer.WriteDatabase(db)
+	if err != nil {
+		t.Fatalf("WriteDatabase failed: %v", err)
+	}
+
+	output := buf.String()
+
+	// Print output for debugging
+	t.Logf("Generated SQL:\n%s", output)
+
+	// Verify unique constraints are present
+	if !strings.Contains(output, "-- Unique constraints for schema: public") {
+		t.Errorf("Output missing unique constraints header")
+	}
+	if !strings.Contains(output, "ADD CONSTRAINT uq_email UNIQUE (email)") {
+		t.Errorf("Output missing uq_email unique constraint\nFull output:\n%s", output)
+	}
+	if !strings.Contains(output, "ADD CONSTRAINT uq_guid UNIQUE (guid)") {
+		t.Errorf("Output missing uq_guid unique constraint\nFull output:\n%s", output)
+	}
+}
+
 func TestWriteTable(t *testing.T) {
 	// Create a single table
 	table := models.InitTable("products", "public")
@@ -438,3 +508,130 @@ func TestColumnSizeSpecifiers(t *testing.T) {
 		}
 	}
 }
+
+func TestGenerateAddColumnStatements(t *testing.T) {
+	// Create a test database with tables that have new columns
+	db := models.InitDatabase("testdb")
+	schema := models.InitSchema("public")
+
+	// Create a table with columns
+	table := models.InitTable("users", "public")
+
+	// Existing column
+	idCol := models.InitColumn("id", "users", "public")
+	idCol.Type = "integer"
+	idCol.NotNull = true
+	idCol.Sequence = 1
+	table.Columns["id"] = idCol
+
+	// New column to be added
+	emailCol := models.InitColumn("email", "users", "public")
+	emailCol.Type = "varchar"
+	emailCol.Length = 255
+	emailCol.NotNull = true
+	emailCol.Sequence = 2
+	table.Columns["email"] = emailCol
+
+	// New column with default
+	statusCol := models.InitColumn("status", "users", "public")
+	statusCol.Type = "text"
+	statusCol.Default = "active"
+	statusCol.Sequence = 3
+	table.Columns["status"] = statusCol
+
+	schema.Tables = append(schema.Tables, table)
+	db.Schemas = append(db.Schemas, schema)
+
+	// Create writer
+	options := &writers.WriterOptions{}
+	writer := NewWriter(options)
+
+	// Generate ADD COLUMN statements
+	statements, err := writer.GenerateAddColumnsForDatabase(db)
+	if err != nil {
+		t.Fatalf("GenerateAddColumnsForDatabase failed: %v", err)
+	}
+
+	// Join all statements to verify content
+	output := strings.Join(statements, "\n")
+	t.Logf("Generated ADD COLUMN statements:\n%s", output)
+
+	// Verify expected elements
+	expectedStrings := []string{
+		"ALTER TABLE public.users ADD COLUMN id integer NOT NULL",
+		"ALTER TABLE public.users ADD COLUMN email varchar(255) NOT NULL",
+		"ALTER TABLE public.users ADD COLUMN status text DEFAULT 'active'",
+		"information_schema.columns",
+		"table_schema = 'public'",
+		"table_name = 'users'",
+		"column_name = 'id'",
+		"column_name = 'email'",
+		"column_name = 'status'",
+	}
+
+	for _, expected := range expectedStrings {
+		if !strings.Contains(output, expected) {
+			t.Errorf("Output missing expected string: %s\nFull output:\n%s", expected, output)
+		}
+	}
+
+	// Verify DO blocks are present for conditional adds
+	doBlockCount := strings.Count(output, "DO $$")
+	if doBlockCount < 3 {
+		t.Errorf("Expected at least 3 DO blocks (one per column), got %d", doBlockCount)
+	}
+
+	// Verify IF NOT EXISTS logic
+	ifNotExistsCount := strings.Count(output, "IF NOT EXISTS")
+	if ifNotExistsCount < 3 {
+		t.Errorf("Expected at least 3 IF NOT EXISTS checks (one per column), got %d", ifNotExistsCount)
+	}
+}
+
+func TestWriteAddColumnStatements(t *testing.T) {
+	// Create a test database
+	db := models.InitDatabase("testdb")
+	schema := models.InitSchema("public")
+
+	// Create a table with a new column to be added
+	table := models.InitTable("products", "public")
+
+	idCol := models.InitColumn("id", "products", "public")
+	idCol.Type = "integer"
+	table.Columns["id"] = idCol
+
+	// New column with various properties
+	descCol := models.InitColumn("description", "products", "public")
+	descCol.Type = "text"
+	descCol.NotNull = false
+	table.Columns["description"] = descCol
+
+	schema.Tables = append(schema.Tables, table)
+	db.Schemas = append(db.Schemas, schema)
+
+	// Create writer with output to buffer
+	var buf bytes.Buffer
+	options := &writers.WriterOptions{}
+	writer := NewWriter(options)
+	writer.writer = &buf
+
+	// Write ADD COLUMN statements
+	err := writer.WriteAddColumnStatements(db)
+	if err != nil {
+		t.Fatalf("WriteAddColumnStatements failed: %v", err)
+	}
+
+	output := buf.String()
+	t.Logf("Generated output:\n%s", output)
+
+	// Verify output contains expected elements
+	if !strings.Contains(output, "ALTER TABLE public.products ADD COLUMN id integer") {
+		t.Errorf("Output missing ADD COLUMN for id\nFull output:\n%s", output)
+	}
+	if !strings.Contains(output, "ALTER TABLE public.products ADD COLUMN description text") {
+		t.Errorf("Output missing ADD COLUMN for description\nFull output:\n%s", output)
+	}
+	if !strings.Contains(output, "DO $$") {
+		t.Errorf("Output missing DO block\nFull output:\n%s", output)
+	}
+}

pkg/writers/sqlexec/writer.go

@@ -23,6 +23,11 @@ func NewWriter(options *writers.WriterOptions) *Writer {
 	}
 }
 
+// Options returns the writer options (useful for reading execution results)
+func (w *Writer) Options() *writers.WriterOptions {
+	return w.options
+}
+
 // WriteDatabase executes all scripts from all schemas in the database
 func (w *Writer) WriteDatabase(db *models.Database) error {
 	if db == nil {
@@ -92,6 +97,22 @@ func (w *Writer) executeScripts(ctx context.Context, conn *pgx.Conn, scripts []*
 		return nil
 	}
 
+	// Check if we should ignore errors
+	ignoreErrors := false
+	if val, ok := w.options.Metadata["ignore_errors"].(bool); ok {
+		ignoreErrors = val
+	}
+
+	// Track failed scripts and execution counts
+	var failedScripts []struct {
+		name     string
+		priority int
+		sequence uint
+		err      error
+	}
+	successCount := 0
+	totalCount := 0
+
 	// Sort scripts by Priority (ascending), Sequence (ascending), then Name (ascending)
 	sortedScripts := make([]*models.Script, len(scripts))
 	copy(sortedScripts, scripts)
@@ -111,18 +132,49 @@ func (w *Writer) executeScripts(ctx context.Context, conn *pgx.Conn, scripts []*
 			continue
 		}
 
+		totalCount++
 		fmt.Printf("Executing script: %s (Priority=%d, Sequence=%d)\n",
 			script.Name, script.Priority, script.Sequence)
 
 		// Execute the SQL script
 		_, err := conn.Exec(ctx, script.SQL)
 		if err != nil {
-			return fmt.Errorf("failed to execute script %s (Priority=%d, Sequence=%d): %w",
+			if ignoreErrors {
+				fmt.Printf("⚠ Error executing %s: %v (continuing due to --ignore-errors)\n", script.Name, err)
+				failedScripts = append(failedScripts, struct {
+					name     string
+					priority int
+					sequence uint
+					err      error
+				}{
+					name:     script.Name,
+					priority: script.Priority,
+					sequence: script.Sequence,
+					err:      err,
+				})
+				continue
+			}
+			return fmt.Errorf("script %s (Priority=%d, Sequence=%d): %w",
 				script.Name, script.Priority, script.Sequence, err)
 		}
 
+		successCount++
 		fmt.Printf("✓ Successfully executed: %s\n", script.Name)
 	}
 
+	// Store execution results in metadata for caller
+	w.options.Metadata["execution_total"] = totalCount
+	w.options.Metadata["execution_success"] = successCount
+	w.options.Metadata["execution_failed"] = len(failedScripts)
+
+	// Print summary of failed scripts if any
+	if len(failedScripts) > 0 {
+		fmt.Printf("\n⚠ Failed Scripts Summary (%d failed):\n", len(failedScripts))
+		for i, failed := range failedScripts {
+			fmt.Printf("  %d. %s (Priority=%d, Sequence=%d)\n     Error: %v\n",
+				i+1, failed.name, failed.priority, failed.sequence, failed.err)
+		}
+	}
+
 	return nil
 }