- publishing free software manuals
PostgreSQL Reference Manual - Volume 2 - Programming Guide
by The PostgreSQL Global Development Group
Paperback (6"x9"), 408 pages
ISBN 0954612035
RRP £19.95 ($34.95)

Sales of this book support the PostgreSQL project! Get a printed copy>>>

9.9 Errors and Messages

Use the RAISE statement to report messages and raise errors.

RAISE level 'format' [, expression [, ...]];

Possible levels are DEBUG, LOG, INFO, NOTICE, WARNING, and EXCEPTION. EXCEPTION raises an error (which normally aborts the current transaction); the other levels only generate messages of different priority levels. Whether messages of a particular priority are reported to the client, written to the server log, or both is controlled by the log_min_messages and client_min_messages configuration variables. See Volume 3: Server Configuration for more information.

Inside the format string, % is replaced by the next optional argument's string representation. Write %% to emit a literal %. Arguments can be simple variables or expressions, and the format must be a simple string literal.

In this example, the value of v_job_id will replace the % in the string:

RAISE NOTICE 'Calling cs_create_job(%)', v_job_id;

This example will abort the transaction with the given error message:

RAISE EXCEPTION 'Nonexistent ID --> %', user_id;

RAISE EXCEPTION presently always generates the same SQLSTATE code, P0001, no matter what message it is invoked with. It is possible to trap this exception with EXCEPTION ... WHEN RAISE_EXCEPTION THEN ... but there is no way to tell one RAISE from another.

ISBN 0954612035PostgreSQL Reference Manual - Volume 2 - Programming GuideSee the print edition