I have this database structure :
Designer
I'm trying to implement this trigger so when a thread has reply, the number_replies goes up on every insertion of a thread if the parentId is not NULL
DELIMITER $$
CREATE TRIGGER `reply_count` AFTER INSERT ON `threads` FOR EACH ROW BEGIN
IF NEW.parentId != NULL THEN
UPDATE
threads
SET
threads.number_replies = threads.number_replies + 1
WHERE
threads.id = NEW.parentId;
END IF ;
END $$ DELIMITER ;
I don't get any errors but it is not working. Thoughts?
Related
Given 2 simple procedures
DELIMITER $$
CREATE PROCEDURE simpleproc()
BEGIN
UPDATE mytable SET name = 'bbb' WHERE id = 1;
DO SLEEP(15);
END
$$ DELIMITER ;
DELIMITER $$
CREATE PROCEDURE simpleproc2()
BEGIN
UPDATE mytable SET name = 'jjj' WHERE id = 1;
END
$$ DELIMITER ;
Then in one connection (in mysql workbench) I run first procedure:
call simpleproc();
and in second connection, run second procedure
call simpleproc2();
What surprised me, is that second transaction no waits for first and executes immediately.
What I missed? why first transaction no locks row id=1?
Table mytable have InnoDB engine
I have a MySQL table , look like this
t id lang title
1 7 en_UK my_title
1 7 kh_KH
I want write a trigger that update title to my_title with the same id is 7
Result
t id lang title
1 7 en_UK my_title
1 7 kh_KH my_title
From my understanding.
DELIMITER $$
CREATE TRIGGER upd_title BEFORE UPDATE ON `term`
FOR EACH ROW BEGIN
IF (NEW.title IS NULL OR NEW.title= '') THEN
SET NEW.title= ??? ;
END IF;
END$$
DELIMITER ;
[UPDATE1]->not works (trigger not being created)
DELIMITER $$
DROP TRIGGER IF EXISTS `update_category_after_insert`
CREATE TRIGGER `update_category` AFTER INSERT ON `categories`
FOR EACH ROW BEGIN
DECLARE loc_title text;
IF (NEW.libelle_categorie IS NULL OR NEW.libelle_categorie= '') THEN
select libelle_categorie into loc_title from categories where NEW.num_noeud= num_noeud and langue = 'en_UK';
SET NEW.libelle_categorie = loc_title;
END IF;
END
DELIMITER ;
[UPDATE2]
DELIMITER $$
CREATE TRIGGER ``update_category_after_insert`` BEFORE INSERT ON `categories`
FOR EACH ROW BEGIN
DECLARE loc_title text;
IF (NEW.libelle_categorie IS NULL OR NEW.libelle_categorie= '') THEN
select libelle_categorie into loc_title from categories where NEW.num_noeud= num_noeud and langue = 'en_UK';
SET NEW.libelle_categorie = loc_title;
END IF;
END
DELIMITER ;
Finally , I found the good solution for my case
UPDATE categories c INNER JOIN categories c2 ON (
c.num_noeud = c2.num_noeud
) SET c.libelle_categorie = c2.`libelle_categorie`
Can you clarify?
Are you trying to pull the value from the title column in the 'en_UK' row that exists when you insert an new row with the same id that HAS the title column not entered?
okay
CREATE TRIGGER upd_title BEFORE UPDATE ON `term`
FOR EACH ROW BEGIN
DECLARE loc_title VARCHAR(20);
IF (NEW.title IS NULL OR NEW.title= '') THEN
select title into loc_title from term where NEW.id = id and lang = 'en_UK';
SET NEW.title= loc_title;
END IF;
END
This should do the trick.
This was my trigger def:
CREATE DEFINER = CURRENT_USER TRIGGER `therinks`.`glreturndata_BEFORE_UPDATE` BEFORE UPDATE ON `glreturndata` FOR EACH ROW
BEGIN
DECLARE myVal VARCHAR(20);
if NEW.DESCRIPTION IS NULL or new.description = '' THEN
SELECT min(description) into myVal from glreturndata where category = NEW.category and new.idglreturndata <> idglreturndata;
Set NEW.DESCRIPTION = myval;
end if;
END
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.
my problem is as follows:
Table A contains list of "Tasks"
Table B contains "TaskProgress" - just an information about time spent on task, user ID, task ID and note
On table A (Tasks), I have trigger, which updates datetime of last change - column DateChanged (intended to capture datetime of edits made by user)
On table B (TaskProgress) I have trigger, which updates total time spent on a task (sum all times for given Task_ID and update column TotalTime in table A)
I wish to update DateChanged in Table A only when user mades the update (which is every time except when trigger on table B updates TotalTime)
So I wonder, whether there is a way how to tell the database not to fire TRIGGER when updating the values in another trigger.
/* set date of last change and date od closing of task */
DELIMITER $$
CREATE TRIGGER before_tasks_update
BEFORE UPDATE ON tasks
FOR EACH ROW BEGIN
SET new.DateChanged = NOW();
IF new.Status_ID = 3 THEN
SET new.DateClosed = NOW();
END IF;
END$$
DELIMITER ;
/* set total time spent on task */
DELIMITER $$
CREATE TRIGGER after_taskprogress_insert
AFTER INSERT ON taskprogress
FOR EACH ROW BEGIN
DECLARE sumtime TIME;
SET #sumtime := (SELECT SEC_TO_TIME( SUM( TIME_TO_SEC( `timeSpent` ) ) )
FROM taskprogress WHERE Task_ID = new.Task_ID);
UPDATE `tasks` SET TimeReal = #sumtime WHERE ID = new.Task_ID;
END $$
DELIMITER ;
I use MySQL 5.5.40
Thanks, zbynek
Add a check to verify that the update implies a new TimeReal value,since only the second trigger updates that column.
DELIMITER $$
CREATE TRIGGER before_tasks_update
BEFORE UPDATE ON tasks
FOR EACH ROW BEGIN
IF new.TimeReal=old.TimeReal THEN SET new.DateChanged = NOW();
END IF;
IF new.TimeReal=old.TimeReal AND new.Status_ID = 3 THEN
SET new.DateClosed = NOW();
END IF;
END$$
DELIMITER ;
hey guys can someone point me whats wrong in my mysql code
im trying to create a stored procedure called in a trigger
were a user insert a new book in the books table, the bookqty table insert if callNumber does not exist and updates when exist, but in some point the insert query is not working
but the update query works fine
thank you in advance
use librarydb;
drop procedure if exists intoBooksQty;
delimiter $$
create procedure intoBooksQty(in newcallNumber varchar(10))
begin
if not exists (select * from books where callNumber = newcallNumber) then
insert into librarydb.bookqty(callNumber,bookQty,bookqtyOut) values (newcallNumber, 1,0);
else
update bookqty set bookQty = bookQty + 1 where callNumber = newCallNumber;
end if;
end$$
delimiter ;
One option is to make a UPSERT.
DELIMITER //
CREATE PROCEDURE `intoBooksQty`(`newcallNumber` VARCHAR(10))
BEGIN
INSERT INTO `bookqty` (`callNumber`, `bookQty`, `bookqtyOut`)
SELECT `newcallNumber`, 1, 0
FROM `books`
WHERE `callNumber` = `newcallNumber`
ON DUPLICATE KEY UPDATE `bookQty` = `bookQty` + 1;
END//
DELIMITER ;
SQL Fiddle demo
My first time using triggers. Can anyone please explain why this trigger won't work? The error I'm getting is inconclusive (error near '' at line 5)
create trigger queue after update on downloads
for each row
begin
if NEW.completed = 1 then
insert into s_queue ( website_id ) values ( NEW.website_id );
end if;
end;
You need to change the delimiter from ; to something else, before defining any stored procedure/functions or triggers.
delimiter ||
create trigger queue after update on downloads
for each row
begin
if NEW.completed = 1 then
insert into s_queue ( website_id ) values ( NEW.website_id );
end if;
end||
delimiter;