hibernate/hibernate-orm · error · UnsupportedOperationException

GaussDB only supports accessing REF_CURSOR parameters by pos

Error message

GaussDB only supports accessing REF_CURSOR parameters by position

What it means

Dialect.getResultSet(CallableStatement, name) is the by-name variant for retrieving REF_CURSOR out-parameters. GaussDB (per GaussDBDialect) only supports accessing refcursor parameters by position, so any code path that asks for a cursor by name throws UnsupportedOperationException immediately.

Source

Thrown at hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/GaussDBDialect.java:908

		return SelectItemReferenceStrategy.POSITION;
	}

	@Override
	public CallableStatementSupport getCallableStatementSupport() {
		return GaussDBCallableStatementSupport.INSTANCE;
	}

	@Override
	public ResultSet getResultSet(CallableStatement statement, int position) throws SQLException {
		if ( position != 1 ) {
			throw new UnsupportedOperationException( "GaussDB only supports REF_CURSOR parameters as the first parameter" );
		}
		return (ResultSet) statement.getObject( 1 );
	}

	@Override
	public ResultSet getResultSet(CallableStatement statement, String name) throws SQLException {
		throw new UnsupportedOperationException( "GaussDB only supports accessing REF_CURSOR parameters by position" );
	}

	@Override
	public boolean qualifyIndexName() {
		return false;
	}

	@Override
	public IdentityColumnSupport getIdentityColumnSupport() {
		return GaussDBIdentityColumnSupport.INSTANCE;
	}

	@Override
	public boolean supportsExpectedLobUsagePattern() {
		return false;
	}

	@Override

View on GitHub (pinned to fad1729dce)

Solutions

1. Register the REF_CURSOR parameter by position (1) instead of by name and access the result positionally
2. Declare the procedure call with positional parameters throughout on GaussDB - the driver requires it for cursors
3. Keep named declarations for other databases but branch the GaussDB persistence unit to a positional variant
4. Verify position 1 usage at the same time - GaussDB only supports the first parameter as a cursor

Example fix

// before (named refcursor, throws on GaussDB)
@NamedStoredProcedureQuery(name = "fetchRows", procedureName = "fetch_rows",
  parameters = @StoredProcedureParameter(name = "cur", mode = ParameterMode.REF_CURSOR))

// after (positional refcursor at position 1)
@NamedStoredProcedureQuery(name = "fetchRows", procedureName = "fetch_rows",
  parameters = @StoredProcedureParameter(position = 1, mode = ParameterMode.REF_CURSOR))

Dialect d = sessionFactory.getJdbcServices().getDialect();
if (d instanceof GaussDBDialect && hasNamedRefCursorParameter(call)) {
    call = toPositionalCall(call); // name 'cur' -> position 1, ParameterMode.REF_CURSOR
}

static boolean namedRefCursorSafe(Dialect d) {
    return !(d instanceof GaussDBDialect);
}

try {
    results = namedQuery.getResultList();
} catch (UnsupportedOperationException e) {
    if (e.getMessage().contains("by position")) {
        // re-register parameters positionally and retry
    } else throw e;
}

When it happens

Trigger: Using named REF_CURSOR parameters with GaussDB: @NamedStoredProcedureQuery with a parameterName of ParameterMode.REF_CURSOR type, or calling StoredProcedureQuery.getResultList after registering the cursor by name - Hibernate resolves names and ends up in the by-name hook.

Common situations: Named-parameter stored-procedure code written for Oracle/PostgreSQL being pointed at GaussDB; annotation-based procedure declarations that prefer names for readability; shared persistence units across databases.

Related errors

• JDBC driver does not support named parameters for setArray.
• GaussDB only supports REF_CURSOR parameters as the first par
• Cannot mix named parameters and REF_CURSOR parameter on Post
• SingleStore does not support resultsets via stored procedure
• Unexpected error extracting REF_CURSOR parameter [{}]

AI-assisted analysis of hibernate/hibernate-orm@fad1729dce (2026-08-22). Data as JSON: /api/errors/74639aad0a448602. Report an issue: GitHub.