Display warnings from the last executed statement. View warning codes, messages, and levels for recent operations.
SHOW WARNINGS shows the error, warning, and note messages that resulted from the last statement that generated messages in the current session. It shows nothing if the last statement used a table and generated no messages. (That is, a statement that uses a table but generates no messages clears the message list.) Statements that do not use tables and do not generate messages have no effect on the message list.
A note is different to a warning in that it only appears if the variable is set to 1 (the default), and is not converted to an error if is enabled.
A related statement, , shows only the errors.
The SHOW COUNT(*) WARNINGS statement displays the total number of errors, warnings, and notes. You can also retrieve this number from the variable:
The value of might be greater than the number of messages displayed by SHOW WARNINGS if the system variable is set so low that not all messages are stored.
The LIMIT clause has the same syntax as for the .
SHOW WARNINGS can be used after to see how a query is internally rewritten by MariaDB.
If the server variable is set to 1, Notes are included in the output of SHOW WARNINGS; if it is set to 0, this statement will not show (or count) Notes.
The results of SHOW WARNINGS and SHOW COUNT(*) WARNINGS are directly sent to the client. If you need to access those information in a stored program, you can use the statement instead.
The client also has a number of options related to warnings. The \W command will show warnings after every statement, while \w will disable this. Starting the client with the --show-warnings option will show warnings after every statement.
MariaDB implements a stored routine error stack trace. SHOW WARNINGS can also be used to show more information. See the example below.
Displaying a stack trace:
SHOW WARNINGS displays a stack trace, showing where the error actually happened:
Line 4 in test.p1 is the OPEN command which actually raised the error.
Line 3 in test.p2 is the CALL statement, calling p1 from p2.
This page is licensed: GPLv2, originally from
SHOW WARNINGS [LIMIT [offset,] row_count]
SHOW ERRORS [LIMIT row_count OFFSET offset]
SHOW COUNT(*) WARNINGSSHOW COUNT(*) WARNINGS;
SELECT @@warning_count;SELECT 1/0;
+------+
| 1/0 |
+------+
| NULL |
+------+
SHOW COUNT(*) WARNINGS;
+-------------------------+
| @@session.warning_count |
+-------------------------+
| 1 |
+-------------------------+
SHOW WARNINGS;
+---------+------+---------------+
| Level | Code | Message |
+---------+------+---------------+
| Warning | 1365 | Division by 0 |
+---------+------+---------------+DELIMITER $$
CREATE OR REPLACE PROCEDURE p1()
BEGIN
DECLARE c CURSOR FOR SELECT * FROM not_existing;
OPEN c;
CLOSE c;
END;
$$
CREATE OR REPLACE PROCEDURE p2()
BEGIN
CALL p1;
END;
$$
DELIMITER ;
CALL p2;
ERROR 1146 (42S02): Table 'test.not_existing' doesn't exist
SHOW WARNINGS;
+-------+------+-----------------------------------------+
| Level | Code | Message |
+-------+------+-----------------------------------------+
| Error | 1146 | Table 'test.not_existing' doesn't exist |
| Note | 4091 | At line 6 in test.p1 |
| Note | 4091 | At line 4 in test.p2 |
+-------+------+-----------------------------------------+