I bulk insert a variable amount of rows in a MySQL table:
INSERT INTO table (col1, col2) VALUES (0,0), (0,1), ..., (0,N)
The first column is always the same, the second column changes in every entry. Now I want to implement a MySQL trigger that uses col1 to update another table. E.g.
DELIMITER //
CREATE TRIGGER updateOtherTable AFTER INSERT ON table
FOR EACH ROW BEGIN
CALL someProcedure(NEW.col1);
END;
//
However, that would execute someProcedure() N times which is not necessary since col1 is always the same for each INSERT.
Is it possible to call this trigger only once and if so, how?
I do not think you can prevent the execution of the trigger for each row.
One option is to use a 9.4. User-Defined Variables (be careful with User-Defined Variables) that controls whether to make the call to the stored procedure.
Something like:
DELIMITER //
CREATE TRIGGER `updateOtherTable` AFTER INSERT ON `table`
FOR EACH ROW
BEGIN
IF #`callSomeProcedure` THEN
SET #`callSomeProcedure` := NULL;
CALL `someProcedure`(NEW.`col1`);
END IF;
END//
DELIMITER ;
SQL Fiddle example
Related
I have this code for the trigger:
CREATE TRIGGER `insert_after` AFTER INSERT ON `hyk50_0001`
FOR EACH ROW BEGIN
INSERT INTO hyk50_0001_copy(Fecha)
SELECT Fecha FROM hyk50_0001
END;
but doesn't work, it says a syntax error but I didn't see it
I'm using Navicat. And hyk50_0001_copy it's a identical copy of hyk50_0001.
The target is take the new row of hyk50_0001 and INSERT in hyk50_0001_copy
I want put all the database, but if it doesn't work with only a value I can't progress.
I don't see a syntax error, but I assume you intend:
DELIMITER $$
CREATE TRIGGER `insert_after` AFTER INSERT ON `hyk50_0001`
FOR EACH ROW
BEGIN
INSERT INTO hyk50_0001_copy(Fecha)
VALUES (new.Fecha)
END;$$
DELIMITER ;
That is, you probably want to insert only the row that was just created.
I'm trying to create a trigger, however I keep getting back a syntax error.
Here's the statement:
DELIMITER $$
CREATE TRIGGER `swtalentbank`.`after_candidate_insert`
AFTER INSERT ON `Candidates` FOR EACH ROW
BEGIN
INSERT INTO useradmin (username, talent)
VALUES (NEW.email, 1);
UPDATE `Candidates` SET UserID = useradmin.userid where useradmin.username = NEW.email;
END
DELIMITER ;
I have a registration form on my site. When a person registers it populates the Candidates table with their profile information.
In the Candidates table, there are various fields, two of them being 'email' and 'UserID'.
UserID is also the PK in 'useradmin', so I'm linking the two up.
So when a user registers, I need to insert a record into 'useradmin' with the email address that's just been used to register, and then update the 'Candidates' table, with UserID that's just been created in 'useradmin'.
I hope this makes sense?
NB. I am changing the delimiter before running the statement.
Besides properly using DELIMITER when creating a trigger you have at least two fundamental issues with your current code:
In MySQL you can't use issue a DML statement (in your case UPDATE) against a table (candidates) on which you defined a trigger (also candidates). Your only option is to use BEFORE trigger and set a value of userid column of a row being inserted to a proper value.
You can't arbitrarily reference a column (useradmin.userid) of a table out of the context like you did in your UPDATE. You didn't joined useradmin table or used it in a subquery.
That being said and assuming that userid in useradmin table is an auto_increment column your trigger might look like this
DELIMITER $$
CREATE TRIGGER after_candidate_insert
BEFORE INSERT ON candidates
FOR EACH ROW
BEGIN
INSERT INTO useradmin (`username`, `talent`) VALUES (NEW.email, 1);
SET NEW.userid = LAST_INSERT_ID();
END$$
DELIMITER ;
Here is SQLFiddle demo
You should use semicolon after end your insert query.
You can use INSERT ... ON DUPLICATE KEY UPDATE syntax for your purpose
try out this...
DELIMITER $$
CREATE TRIGGER `swtalentbank`.`after_candidate_insert`
AFTER INSERT ON `Candidates` FOR EACH ROW
BEGIN
INSERT INTO useradmin (username, talent)
VALUES (NEW.email, 1);
UPDATE `Candidates` SET UserID = useradmin.userid where useradmin.username = NEW.email;
END $$
DELIMITER ;
So I am trying to create trigger that will only execute when a specific column within a table is updated. The table in question is track the column in question is track.track_hits. What I want to do is if that value changes then it inserts a value into a table called play_log. The insert should be the track_id from track and a timestamp.
The code I have done so far is below but it doesn't work, how can it be fixed?
CREATE TRIGGER pi_play AFTER UPDATE ON track
FOR EACH ROW
BEGIN
if :new.track_hits != :old.track_hits
then
INSERT INTO play_log (track_id,access_time)
VALUES (NEW.track_id, NOW())
end if;
END;
NEW and OLD do not need : in front. Also, when creating triggers, you may need to change the delimiter. If you don't change the delimiter, your create trigger statement may be terminated early.
Here's how I would do it:
delimiter |
create trigger pi_play after update on track
for each row
begin
if new.track_hits != old.track_hits then
insert into play_log(track_id, access_time) values (new.track_id, now());
end if;
end|
delimiter ;
Here's the fiddle showing it in action: http://sqlfiddle.com/#!2/3d99d/1 Notice that I changed the delimiter in the schema window to | instead of the default ;. Since SQL uses JDBC and JDBC doesn't take the command DELIMITER, I chose the delimiter.
I have a MySQL trigger using the BEFORE INSERT ON table that calculates a value and updates the same table after a user inserts values in specific columns. This works as expected. But a user makes a mistake in their entry and fixes their error and I want to write a trigger that will update the calculated value after the error has been fixed. Is there a way to achieve this?
A BEFORE UPDATE ON table trigger has access to the existing values in the row as well as newly supplied values, and can set the value of any column in the table, based on whatever conditions and expressions we want.
For example, it's possible to test whether the value of one or more columns of concern has been modified, and then set some other column to some expression.
DELIMITER $$
CREATE TRIGGER my_before_update_trigger
BEFORE UPDATE ON my_table
FOR EACH ROW
BEGIN
IF NOT ((NEW.col1 <=> OLD.col1) AND (NEW.col2 <=> OLD.col2)) THEN
SET NEW.col3 = NEW.col1 * NEW.col2 ;
END IF;
END$$
DELIMITER ;
I have two tables called account and transaction. I need to insert data to transaction automatically when account inserts data. I created this trigger in MySQL. It gives error 1064 (Syntax error). What is the problem?
CREATE TRIGGER upTransaction AFTER INSERT ON account FOR EACH ROW
BEGIN
INSERT INTO transaction VALUES (2,account.openDate,CURTIME(),
account.deposit,account.accNo,
"Teller","Cash","Deposit");
END
MySQL gets confused with semicolons inside the BEGIN END block, so you must use DELIMITER to temporarily force MySQL to use a different delimiter.
Documentation: http://dev.mysql.com/doc/refman/5.5/en/create-trigger.html
DELIMITER //
CREATE TRIGGER upTransaction AFTER INSERT ON account FOR EACH ROW
BEGIN
INSERT INTO transaction VALUES (2,account.openDate,CURTIME(),account.deposit,account.accNo,"Teller","Cash","Deposit");
END//
DELIMITER ;
You probably need to replace:
INSERT INTO transaction VALUES (2,account.openDate,CURTIME(),account.deposit,account.accNo,"Teller","Cash","Deposit");
with:
INSERT INTO transaction VALUES (2,NEW.openDate,CURTIME(),NEW.deposit,NEW.accNo,"Teller","Cash","Deposit");
Here is you original trigger
CREATE TRIGGER upTransaction AFTER INSERT ON account FOR EACH ROW
BEGIN
INSERT INTO transaction VALUES (2,account.openDate,CURTIME(),
account.deposit,account.accNo,
"Teller","Cash","Deposit");
END
Replace account. with NEW. (optional : replace " with ')
DELIMITER $$
CREATE TRIGGER upTransaction AFTER INSERT ON account FOR EACH ROW
BEGIN
INSERT INTO transaction VALUES (2,NEW.openDate,CURTIME(),
NEW.deposit,NEW.accNo,
'Teller','Cash','Deposit');
END $$
DELIMITER ;
CREATE
TRIGGER `event_name` AFTER INSERT
ON `database`.`table`
FOR EACH ROW BEGIN
-- trigger body
-- this code is applied to every
-- inserted/updated/deleted row
END;
Seems like you're missing a table name after 'account'. (edit: or a database name before account, I'm not certain as to what account pertains to)