type details are not supported in MySQL compatibility mode

Error message

type details are not supported in MySQL compatibility mode

What it means

In MySQL compatibility mode, Kingbase does not expose the PostgreSQL catalog views this driver uses to introspect user-defined types, so getTypeDetails refuses the request up front rather than running incompatible SQL. It is a deliberate capability guard.

Source

Thrown at agents/drivers/kingbase-go/kingbase_metadata.go:664

LEFT JOIN %s opc ON opc.oid = r.rngsubopc
LEFT JOIN %s ncan ON ncan.oid = pcan.pronamespace
LEFT JOIN %s ndiff ON ndiff.oid = pdiff.pronamespace
LEFT JOIN %s nopc ON nopc.oid = opc.opcnamespace
WHERE r.rngmultitypid = %%d`, rangeSubtype, rangeTable, typeTable, namespaceTable, typeTable, namespaceTable, procTable, procTable, opclassTable, namespaceTable, namespaceTable, namespaceTable),
		rangeMultirange: fmt.Sprintf(`SELECT mt.typname
FROM %s r
JOIN %s mt ON mt.oid = r.rngmultitypid
WHERE r.rngtypid = %%d`, rangeTable, typeTable),
		collationName: fmt.Sprintf(`SELECT quote_ident(ncl.nspname) || '.' || quote_ident(cl.collname) FROM %s cl JOIN %s ncl ON ncl.oid = cl.collnamespace WHERE cl.oid = %%d`, collationTable, namespaceTable),
	}
}

// getTypeDetails returns read-only details of a user-defined type. MySQL
// compatibility mode is explicitly unsupported instead of running PostgreSQL
// catalog SQL against a MySQL-mode server.
func (s *server) getTypeDetails(schema, name string) (*customTypeDetails, error) {
	if s.mode.mysqlCompat {
		return nil, errors.New("type details are not supported in MySQL compatibility mode")
	}
	schema = strings.TrimSpace(schema)
	name = strings.TrimSpace(name)
	if schema == "" || name == "" {
		return nil, errors.New("schema and type name are required")
	}
	if isSystemSchema(schema) {
		return nil, fmt.Errorf("system schema %s is not supported for custom type details", schema)
	}
	catalog := "sys_catalog"
	if s.mode.postgresCatalog {
		catalog = "pg_catalog"
	}
	prefix := catalogPrefix(catalog)
	queries := customTypeCatalogQueriesFor(catalog, prefix, schema, name)

	rows, err := s.metadataQuery(queries.general)
	if err != nil {

View on GitHub (pinned to c0390bff16)

Solutions

Connect to a Kingbase database in PostgreSQL compatibility mode when type-details introspection is needed
Skip or degrade the type-details feature in the application when mysqlCompat mode is detected
Verify the DSN/target database compatibility mode; the mode may have been chosen unintentionally

Defensive patterns

Strategy: fallback

Validate before calling

if s.mode.mysqlCompat { /* skip type-details or use a degraded code path */ }

Try / catch

details, err := s.getTypeDetails(schema, name); if err != nil && strings.Contains(err.Error(), "MySQL compatibility") { details = nil /* degrade gracefully */ }

Prevention

Detect mysqlCompat mode once at connect time and disable PostgreSQL-catalog features
Document mode-dependent capability limits in your tooling
Confirm the database compatibility mode in the DSN/environment before relying on catalog introspection

When it happens

Trigger: Calling the type-details metadata API for a user-defined type while the server connection was established in MySQL compatibility mode (s.mode.mysqlCompat == true).

Common situations: Pointing the driver at a Kingbase instance initialized with a MySQL-mode database; reusing a metadata tool written for PostgreSQL mode against a MySQL-mode server; misconfigured DSN selecting the wrong compatibility mode.

Related errors

AI-assisted analysis of t8y2/dbx@c0390bff16 (2026-09-05). Data as JSON: /api/errors/ef460397cc18f116. Report an issue: GitHub.