NexusDB V3 Manual

SIGNAL statement

Signal an exception condition.

Syntax

<signal statement> ::= SIGNAL <character string literal>

Usage

The SIGNAL statement is used to throw an exception with the message specified by the character string literal.

Examples

      SIGNAL 'Dummy Exception.';

      DECLARE v1, v2 DOUBLE PRECISION;

      SET v1 = RAND;

      SET v2 = RAND;

      IF ( v1 = v2 ) THEN

SIGNAL 'The values are equal.';

      ELSE

SIGNAL 'The values are different.';

      END IF;

3) The following example shows the SIGNAL statement used in the CATCH clause of a TRY statement:

      START TRANSACTION;

      TRY

DROP TABLE garbage;

COMMIT;

      CATCH POSITION( 'Unable to open table' IN ERROR_MESSAGE ) <> 0

ROLLBACK;

SIGNAL 'The table couldn''t be dropped.' || CHR(13) || 'The transaction was rolled back.';

      END;

Conformance