MySQL - Trigger for updating same table after insert

Question

Here\'s what I\'m trying to do:

When there\'s a new INSERT into the table ACCOUNTS, I need to update the row in ACCOUNTS where

Answer 1

It seems that you can't do all this in a trigger. According to the documentation:

Within a stored function or trigger, it is not permitted to modify a table that is already being used (for reading or writing) by the statement that invoked the function or trigger.

According to this answer, it seems that you should:

create a stored procedure, that inserts into/Updates the target table, then updates the other row(s), all in a transaction.

With a stored proc you'll manually commit the changes (insert and update). I haven't done this in MySQL, but this post looks like a good example.

Answer 2

Had the same problem but had to update a column with the id that was about to enter, so you can make an update should be done BEFORE and AFTER not BEFORE had no id so I did this trick

DELIMITER $$
DROP TRIGGER IF EXISTS `codigo_video`$$
CREATE TRIGGER `codigo_video` BEFORE INSERT ON `videos` 
FOR EACH ROW BEGIN
    DECLARE ultimo_id, proximo_id INT(11);
    SELECT id INTO ultimo_id FROM videos ORDER BY id DESC LIMIT 1;
    SET proximo_id = ultimo_id+1;
    SET NEW.cassette = CONCAT(NEW.cassette, LPAD(proximo_id, 5, '0'));
END$$
DELIMITER ;

Answer 3

DELIMITER $$

DROP TRIGGER IF EXISTS `setEditStatus`$$
CREATE TRIGGER `setEditStatus` **BEFORE** INSERT on ACCOUNTS
FOR EACH ROW BEGIN

    SET NEW.STATUS = 'E';

END$$

DELIMITER ;

Answer 4

On the last entry; this is another trick:

SELECT AUTO_INCREMENT FROM information_schema.tables WHERE table_schema = ... and table_name = ...

Answer 5

Instead you can use before insert and get max pkid for the particular table and then update the maximium pkid table record.

Answer 6

This is how I update a row in the same table on insert

activationCode and email are rows in the table USER. On insert I don't specify a value for activationCode, it will be created on the fly by MySQL.

Change username with your MySQL username and db_name with your db name.

CREATE DEFINER=`username`@`localhost` 
       TRIGGER `db_name`.`user_BEFORE_INSERT` 
       BEFORE INSERT ON `user` 
       FOR EACH ROW
         BEGIN
            SET new.activationCode = MD5(new.email);
         END