mySQL 存储过程没有给我错误消息

Question

The following stored procedure works as intended BUT if I force an error (see intentional type-o in INSERT statement) I don't get any error information.

I created a table called error_check and tried inserting error info into there to see if I could get some more information, but when there is an error, no rows are added to the table. (When I take out the type-o, I get a new row with nulls in it, as expected.)

This used to work, so I'm sure it is something I added by mistake.

CREATE DEFINER=`root`@`localhost` PROCEDURE `addClassToMasterList`( IN begin_date VARCHAR(10), IN day_num INT,
                               IN startTime VARCHAR(10), IN endTime VARCHAR (20), IN loc_id INT, IN studio VARCHAR(20),
                               IN class_name VARCHAR(45), IN owner_id INT,
                               IN club_id INT, OUT return_id VARCHAR(250))
BEGIN

DECLARE EXIT HANDLER FOR SQLEXCEPTION, NOT FOUND, SQLWARNING
BEGIN
    ROLLBACK;  
    GET DIAGNOSTICS CONDITION 1 @sqlstate = RETURNED_SQLSTATE, 
                                @errno = MYSQL_ERRNO, 
                                @text = MESSAGE_TEXT;
    SET @display_error = CONCAT("ERROR ", @errno, " (", @sqlstate, "): ", @text);
END;   /*end of exception handing*/

SET @formatted_date = STR_TO_DATE(begin_date, '%m/%d/%Y');

/* Save all data as a new row in the Master Schedule */
INSERT INTO master_class_list_typeo_here
VALUES (null, 
    day_num, 
    @formatted_date, 
    null,
    startTime, 
    endTime, 
    loc_id, 
    studio,
    class_name, 
    owner_id, 
    club_id); 

SELECT LAST_INSERT_ID() INTO @new_id;

/* Put bits of error into a table so I can see what is going on. */
INSERT INTO error_check
VALUES (null, @display_error, @text, @errno);

/* If an error message was generated, return the error.
   Otherwise, return the new id that was automatically created. */
SELECT IF (@display_error, @display_error, @new_id) INTO return_id;
/* Also tried:  SELECT @display_error INTO return_id;  */

END

Answer 1

Try:

...
GET STACKED DIAGNOSTICS CONDITION 1
...

13.6.7.3 GET DIAGNOSTICS Syntax

...

The keyword STACKED means to retrieve information from the second diagnostics area, which is available only if the current context is a condition handler.

...

See db-fiddle .

Answer 2

Place your INSERT INTO error_check statement within the BEGIN...END logical block of your exception handling, using INSERT INTO... SELECT... like so:

...
BEGIN
    -- ROLLBACK;  
    GET DIAGNOSTICS CONDITION 1 @sqlstate = RETURNED_SQLSTATE, 
                                @errno = MYSQL_ERRNO, 
                                @text = MESSAGE_TEXT;
    SET @display_error = CONCAT("ERROR ", @errno, " (", @sqlstate, "): ", @text);

    /* Put bits of error into a table so I can see what is going on. */
    INSERT INTO error_check
    SELECT null, @display_error, @text, @errno;

END;   /*end of exception handing*/
...

This works for me. Note that I also commented out the ROLLBACK