GaussDB(DWS) Stored Procedure Debugging¶
Syntax¶
RAISE has the following five syntax formats:
Figure 1 raise_format::=¶
Figure 2 raise_condition::=¶
Figure 3 raise_sqlstate::=¶
Figure 4 raise_option::=¶
Figure 5 raise::=¶
Parameter description:
The level option is used to specify the error level, that is, DEBUG, LOG, INFO, NOTICE, WARNING, or EXCEPTION (default). EXCEPTION throws an error that normally terminates the current transaction and the others only generate information at their levels. The log_min_messages and client_min_messages parameters control whether the error messages of specific levels are reported to the client and are written to the server log.
format: specifies the error message text to be reported, a format character string. The format character string can be appended with an expression for insertion to the message text. In a format character string, % is replaced by the parameter value attached to format and %% is used to print %. For example:
--v_job_id replaces % in the character string. RAISE NOTICE 'Calling cs_create_job(%)',v_job_id;
option = expression: inserts additional information to an error report. The keyword option can be MESSAGE, DETAIL, HINT, or ERRCODE, and each expression can be any character string.
MESSAGE: specifies the error message text. This option cannot be used in a RAISE statement that contains a format character string in front of USING.
DETAIL: specifies detailed information of an error.
HINT: prints hint information.
ERRCODE: designates an error code (SQLSTATE) to a report. A condition name or a five-character SQLSTATE error code can be used.
condition_name: specifies the condition name corresponding to the error code.
sqlstate: specifies the error code.
If neither a condition name nor an SQLSTATE is designated in a RAISE EXCEPTION command, the RAISE EXCEPTION (P0001) is used by default. If no message text is designated, the condition name or SQLSTATE is used as the message text by default.
Important
If the SQLSTATE designates an error code, the error code is not limited to a defined error code. It can be any error code containing five digits or ASCII uppercase rather than 00000. Do not use an error code ended with three zeros because this kind of error codes is type codes and can be captured by the whole category.
Note
The syntax described in Figure 5 does not append any parameter. This form is used only for the EXCEPTION statement in a BEGIN block so that the error can be re-processed.
Examples¶
Display error and hint information when a transaction terminates:
CREATE OR REPLACE PROCEDURE proc_raise1(user_id in integer)
AS
BEGIN
RAISE EXCEPTION 'Noexistence ID --> %',user_id USING HINT = 'Please check your user ID';
END;
/
CALL proc_raise1(300011);
ERROR: Noexistence ID --> 300011
HINT: Please check your user ID
Two methods are available for setting SQLSTATE:
CREATE OR REPLACE PROCEDURE proc_raise2(user_id in integer)
AS
BEGIN
RAISE 'Duplicate user ID: %',user_id USING ERRCODE = 'unique_violation';
END;
/
\set VERBOSITY verbose
call proc_raise2(300011);
ERROR: Duplicate user ID: 300011
SQLSTATE: 23505
LOCATION: exec_stmt_raise, pl_exec.cpp:3482
If the main parameter is a condition name or SQLSTATE, the following applies:
RAISE division_by_zero;
RAISE SQLSTATE '22012';
For example:
CREATE OR REPLACE PROCEDURE division(div in integer, dividend in integer)
AS
DECLARE
res int;
BEGIN
IF dividend=0 THEN
RAISE division_by_zero;
RETURN;
ELSE
res := div/dividend;
RAISE INFO 'division result: %', res;
RETURN;
END IF;
END;
/
CALL division(3,0);
ERROR: division_by_zero
Alternatively:
RAISE unique_violation USING MESSAGE = 'Duplicate user ID: ' || user_id;