How to handle an error in mysql

Mysql error processing method: 1. If a 1062 error occurs, execute the SELECT statement; 2. When the SQL select statement does not return a value, set [l_done=1] and continue execution; 3. After an error message is generated Exit the current block or stored procedure; 4. If there is any error, set [l_error] to 1 and then execute.

Mysql error handling method:

1. If there is any error (not NOT FOUND), set l_error Continue execution after being 1:

DECLARE CONTINUE HANDLER FOR SQLEXCEPTION
SET l_error=1;

2. If any error occurs (not NOT FOUND), execute ROLLBACK and generate an error message before exiting the current block or stored procedure.

DECLARE EXIT HANDLER FOR SQLEXCEPTION
BEGIN
ROLLBACK;
SELECT 'Error occurred – terminating';
END;

3. If MySQL 1062 error (duplicate key value) occurs, execute the SELECT statement (send a message to the calling program) and then continue execution

DECLARE CONTINUE HANDER FOR 1062
SELECT 'Duplicate key in index';

4. If SQLSTATE 2300 error (duplicate key value) health value) occurs, execute the SELECT statement (send a message to the calling program) and continue execution

DECLARE CONTINUE HANDER FOR SQLSTATE '23000'
SELECT 'Duplicate key in index';

5. When the cursor or SQL select statement does not return a value, set l_done=1 and continue execution

DECLARE CONTINUE HANDLER FOR NOT
FOUND
SET l_done=1;

6. This example is the same as the previous example except that it uses the SQLSTATE variable instead of the named condition

DECLARE CONTINUE HANDLER FOR SQLSTATE '02000 '
SET l_done=1;

7. This example uses the MySQL error code variable instead of the named condition or SQLSTATE variable. The two examples are the same

DECLARE CONTINUE HANDLER FOR 1329
SET l_done=1;

More related free learning recommendations:mysql tutorial(Video)

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