I'm trying to create a trigger that everytime that insert a new data in my table tb_produto_parent, I need to update the columm cod_prod add one more.
Follow the trigger :
DELIMITER $$
create trigger trgAdicionaUm after insert
on tb_produto_parent
for each row
BEGIN
select cod_prod from tb_produto_parent;
update
tb_produto_parent set cod_prod = cod_prod +1;
END;
When I try to execute the code, MySQL show me a error :
Error Code: 1415 Not allowed to return a result set from a trigger.
Thanks !
There are two major problems with your code
you can't use SELECT on it own in a trigger because a trigger doesn't return a resultset to the client
you can't use DML statements (UPDATE in your case) on the same table (tb_produto_parent) on which you have your trigger in MySQL. Therefore even if you fix the first problem you still won't be able to update any row in tb_produto_parent within the trigger.
The only thing you can do in MySQL trigger is to alter values of columns of a row being inserted by using a BEFORE event for a trigger.
A possible solution is to use a stored procedure instead.
Error Code: 1415 Not allowed to return a result set from a trigger.
Looking at your trigger:
BEGIN
select cod_prod from tb_produto_parent;
update
tb_produto_parent set cod_prod = cod_prod +1;
END;
It would seem the select statement is the cause of this error. Remove it.
Related
I just switched from using Apache's Derby Database to MySQL and still getting familiar with the syntax. I read the documentation about triggers and I think I followed the syntax correctly. However, I'm having problems with BEGIN and END My insert trigger below doesn't work if I put BEGIN and ENDI even tried putting DELIMITER but it doesn't fix it.
CREATE TRIGGER COPY_INSERTED_USERID_TO_ALLUSERS_PERMISSIONS
AFTER INSERT ON ALLUSERS
FOR EACH ROW
BEGIN
INSERT INTO ALLUSERS_ADMIN_PERMISSIONS(USERID)
VALUES(NEW.USERID);
END;
Removing the BEGIN and END makes it work but I'm not able to take full advantage of the compound statements.
CREATE TRIGGER COPY_INSERTED_USERID_TO_ALLUSERS_PERMISSIONS
AFTER INSERT ON ALLUSERS
FOR EACH ROW
INSERT INTO ALLUSERS_ADMIN_PERMISSIONS(USERID)
VALUES(NEW.USERID);
I'd appreciate any help.
Thanks.
Edited:
I tried to follow #Ilanatos advice which works but returns an error on first attempt. I had to refresh the phpmyadmin page to get rid of the error.
Below are the screenshots.
then if I refresh the page(both Firefox and Chrome), I see the trigger.
I don't think it should return an error message during execution of create trigger definition.
Try using the delimiter function when creating your trigger.
DELIMITER $$
CREATE TRIGGER COPY_INSERTED_USERID_TO_ALLUSERS_PERMISSIONS
AFTER INSERT ON ALLUSERS
FOR EACH ROW BEGIN
INSERT INTO ALLUSERS_ADMIN_PERMISSIONS(USERID)
VALUES(NEW.USERID);
END$$
DELIMITER ;
CREATE TRIGGER backupFIDE AFTER UPDATE ON player
FOR EACH ROW
BEGIN
IF (OLD.FIDERating <> NEW.FIDERating) THEN
INSERT INTO playerbackup(PlayerName, OldFIDERating, NewFIDERating)
VALUES(OLD.PlayerName, OLD.FIDERating, NEW.NewFIDERating)
END;
Hi guys, receiving syntax error at line 6 for some reason, been looking online for solution to what might be the cause. Basically looking a simple trigger, that will copy a change change of FIDERating in Player table to a backup table containing OldFIDERating before it was changed, and the NewFIDERating along with the date change was made.
DELIMITER //
CREATE TRIGGER backupFIDE AFTER UPDATE ON player
FOR EACH ROW
BEGIN
IF NEW.FIDERating <> OLD.FIDERating
THEN
INSERT INTO playerbackup(PlayerName, OldFIDERating, NewFIDERating)
VALUES(OLD.PlayerName, OLD.FIDERating, NEW.NewFIDERating);
END IF;
END;
//
DELIMITER ;
I need help converting this MS SQL update trigger to MySQL. My problem is with converting the MS SQL UPDATE() function, which identifies the specific columns that were updated:
ALTER TRIGGER [dbo].[tran_upd_action] ON [dbo].[tran_action]
FOR UPDATE AS
BEGIN
IF ##ROWCOUNT>0
BEGIN
IF update(column1) OR update(column2)
BEGIN
INSERT into tran_indexerqueue
(trankey, trkey2, tranname) SELECT tran_actionid, 0, 'tranaction' from inserted
END
END
END
This does not have the rowcount check, but the basic trigger syntax will be like this. Note that only the Super User role can create a trigger. Also, you have to change the delimiter first, which is usually a big gotcha for MSSQL DBAs.
DELIMITER $$
CREATE TRIGGER `tran_upd_action` AFTER UPDATE ON `tran_action` FOR EACH ROW BEGIN
INSERT INTO tran_indexerqueue
(trankey, trkey2, tranname)
VALUES(OLD.trankey, OLD.trkey2, OLD.tranname);
END $$
DELIMITER ;
The following code works
CREATE
TRIGGER rebuild_course_auto_enrollment_tree_mv AFTER INSERT
ON course_auto_enrollment FOR EACH ROW
DELETE FROM
cron_event_tasks;
If I add the BEGIN ... END as written in the documentation
CREATE
TRIGGER rebuild_course_auto_enrollment_tree_mv AFTER INSERT
ON course_auto_enrollment FOR EACH ROW
BEGIN
DELETE FROM
cron_event_tasks;
END;
This is not working, hmmmm...What am I missing?
Stupid me.
I am using phpmyadmin, and it uses the ; as the delimiter to separate queries.
Solution: change in the query window of phpmyadmin the delimiter to something else and wallah...
Does MySQL permit callbacks in C such that when a change happens in the database, like an insert, that is performed by a different program or by the user at the command line, I can be notified?
I am guessing that it doesn't, because mysqlclient is a library, not a running thread. But I may as well ask.
Create a trigger like so.
DELIMITER $$
CREATE TRIGGER ad_mytable_each AFTER DELETE ON MyTable FOR EACH ROW
BEGIN
#write code that trigger After delete (hence the "ad_" prefix)
#For table MyTable (The _MyTable_ middle)
#On each row that gets inserted (_each suffix)
#
#You can see the old delete values by accesing the "old" virtual table.
INSERT INTO log VALUES (old.id, 'MyTable', old.field1, old.field2, now());
END$$
DELIMITER ;
There are triggers for INSERT, DELETE, UPDATE
And they can fire BEFORE or AFTER the action.
The trigger BEFORE the action can cancel the action by forcing an error, like so.
CREATE TRIGGER bd_mytable_each BEFORE DELETE ON MyTable FOR EACH ROW
BEGIN
#write code that trigger Before delete (hence the "db_" prefix)
declare DoError Boolean;
SET DoError = 0;
IF old.id = 1 THEN SET DoError = 1; END IF;
IF (DoError = 1) THEN SELECT * FROM Table_that_does_not_exist_to_force_error;
#seriously this example is in the manual.
END$$
DELIMITER ;
This will prevent deletion of record 1.
A before UPDATE Trigger can even change the values updated.
CREATE TRIGGER bu_mytable_each BEFORE UPDATE ON MyTable FOR EACH ROW
BEGIN
IF new.text = 'Doon sucks' THEN SET new.text = 'Doon rules';
END$$
DELIMITER ;
Hope you'll be Trigger happy.
MySQL's triggers allow you to hook into insert/update/delete queries and do something additional. You could log them in a separate table, for example.
Well you could attach a trigger to user defined function, and have it call an external program, that would then notify your code..
http://dev.mysql.com/doc/refman/5.0/en/faqs-triggers.html#qandaitem-B-5-1-10
You can use triggers combined with UDFs (user defined functions) so that the corresponding action on the database executes a trigger that calls a C/C++ function.
Just consider that this mechanism runs your code inside the mysql server process, not in the client side.