Method IntrospectSchema

internal/engine/postgresql/analyzer/analyze.go:392–483

IntrospectSchema queries the database to build a catalog containing tables, columns, and enum types for the specified schemas.

(ctx context.Context, schemas []string)

// IntrospectSchema queries the database to build a catalog containing
// tables, columns, and enum types for the specified schemas.
func (a *Analyzer) IntrospectSchema(ctx context.Context, schemas []string) (*catalog.Catalog, error) {
	if a.pool == nil {
		return nil, fmt.Errorf("database connection not initialized")
	}

	c, err := a.pool.Acquire(ctx)
	if err != nil {
		return nil, err
	}
	defer c.Release()

	// Query tables and columns
	rows, err := c.Query(ctx, introspectTablesQuery, schemas)
	if err != nil {
		return nil, fmt.Errorf("introspect tables: %w", err)
	}
	columns, err := pgx.CollectRows(rows, pgx.RowToStructByName[introspectedColumn])
	if err != nil {
		return nil, fmt.Errorf("collect table rows: %w", err)
	}

	// Query enums
	enumRows, err := c.Query(ctx, introspectEnumsQuery, schemas)
	if err != nil {
		return nil, fmt.Errorf("introspect enums: %w", err)
	}
	enums, err := pgx.CollectRows(enumRows, pgx.RowToStructByName[introspectedEnum])
	if err != nil {
		return nil, fmt.Errorf("collect enum rows: %w", err)
	}

	// Build catalog
	cat := &catalog.Catalog{
		DefaultSchema: "public",
		SearchPath:    schemas,
	}

	// Create schema map for quick lookup
	schemaMap := make(map[string]*catalog.Schema)
	for _, schemaName := range schemas {
		schema := &catalog.Schema{Name: schemaName}
		cat.Schemas = append(cat.Schemas, schema)
		schemaMap[schemaName] = schema
	}

	// Group columns by table
	tableMap := make(map[string]*catalog.Table)
	for _, col := range columns {
		key := col.SchemaName + "." + col.TableName
		tbl, exists := tableMap[key]
		if !exists {
			tbl = &catalog.Table{
				Rel: &ast.TableName{
					Schema: col.SchemaName,
					Name:   col.TableName,
				},
			}
			tableMap[key] = tbl