Function GoDuckDBTypeNameToPostgresType

pgtypes/pgtypes.go:257–292

GoDuckDBTypeNameToPostgresType parses a type name reported by the go-duckdb driver into a corresponding pgtype.Type with its precision and scale (if applicable). Unknown types are fallback to text. TODO(fan): Make this function more rigorous for nested types.

(name string)

// GoDuckDBTypeNameToPostgresType parses a type name reported by the go-duckdb driver
// into a corresponding pgtype.Type with its precision and scale (if applicable).
// Unknown types are fallback to text.
//
// TODO(fan): Make this function more rigorous for nested types.
func GoDuckDBTypeNameToPostgresType(name string) (pt *pgtype.Type, precision, scale int32, fallback bool, err error) {
	var list bool
	if strings.HasSuffix(name, "[]") {
		// LIST type
		// Ref: logicalTypeNameList in go-duckdb
		name = strings.TrimSuffix(name, "[]")
		list = true
	}

	if strings.HasPrefix(name, "DECIMAL") {
		// Scan precision and scale from the type name
		// Ref: logicalTypeNameDecimal in go-duckdb
		if _, err = fmt.Sscanf(name, "DECIMAL(%d,%d)", &precision, &scale); err != nil {
			return nil, 0, 0, false, err
		}
		name = "DECIMAL"
	}
	pgTypeName, ok := duckdbTypeNameToPostgresTypeName[name]
	if !ok {
		pgTypeName, fallback = "text", true // Default to text if it is an unknown type
	}
	if list {
		// the pgx/pgtype package prefixes array type names with an underscore:
		// https://github.com/jackc/pgx/blob/master/pgtype/pgtype_default.go
		pgTypeName = `_` + pgTypeName
	}
	pt, ok = DefaultTypeMap.TypeForName(pgTypeName)
	if !ok {
		pt, ok = DefaultTypeMap.TypeForName("text")
		fallback = true
	}
	if !ok {
		return nil, 0, 0, fallback, fmt.Errorf("unsupported type %s", name)
	}
	return
}