I hav a table with several fields. One field is "date_assigned" and the other is "assigned". "date_assigned" has a datatype of timestamp and can be null. "assigned" has a datatype of tinyint and the values are either 0 (default; 'not assigned') or 1 ('assigned').
I would like to create a trigger that would automatically update the "assigned" value to 1 when "date_assigned" is updated with a value (is not null).
I've used triggers before, but have not used them in conjunction with checking if a value is null. I'm unclear on the syntax, so any help would be appreciated. So far, I've tried:
DELIMITER $$
CREATE
TRIGGER `<database>`.`<trigger_name>` AFTER UPDATE
ON `<database>`.`<table>`
FOR EACH ROW BEGIN
IF(NEW.date_assigned IS NOT NULL) THEN
UPDATE <table> SET assigned = '1';
END$$
DELIMITER ;
I just get Error Code: 1064. I looked upo the code, and it appears that it's a syntax error. So what syntax mistake am I making, and is this even the correct 'grammar'?
Try putting BEGIN in a new line as follows.
DELIMITER $$
CREATE
TRIGGER `<database>`.`<trigger_name>` AFTER UPDATE
ON `<database>`.`<table>`
FOR EACH ROW
BEGIN
IF(NEW.date_assigned IS NOT NULL) THEN
UPDATE <table> SET assigned = '1';
END; //Change here also.
$$
DELIMITER ;
This is because of default delimiter in MySQL set to ;. So, the first line should look like DELIMITER $$;
DELIMITER $$;
CREATE TRIGGER `<database>`.`<trigger_name>`
AFTER UPDATE ON `<database>`.`<table>`
FOR EACH ROW BEGIN
IF(NEW.date_assigned IS NOT NULL) THEN
UPDATE <table> SET assigned = '1';
END$$
DELIMITER ;
Related
i have a table which contains columns as "barkoda1,barkoda2,barkoda3,#pdfa1,#pdfa2,#pdfa3", what i'm trying to do is when a record assigned to barkoda1 copy same record to #pdfa1,for example if barkoda1 defined as "1234567890" #pdfa1 should be "1234567890.pdf".
i tried to create a trigger for it, but failed;
DELIMITER //
CREATE TRIGGER pdfdeneme AFTER INSERT
ON finyeb_ba_2369_bio_for_2__r_d_
FOR EACH ROW
BEGIN
UPDATE finyeb_ba_2369_bio_for_2__r_d_ SET `#pdfa1`=NEW.barkoda1;
END//
DELIMITER ;
when i create this trigger,it doesn't return any error but when i add record to table mysql returns "it is already used by statement which invoked this stored function/trigger".
also tried this way
DELIMITER //
CREATE TRIGGER pdfdeneme BEFORE INSERT
ON finyeb_ba_2369_bio_for_2__r_d_
FOR EACH ROW
BEGIN
INSERT INTO finyeb_ba_2369_bio_for_2__r_d_(`#pdfa1`) VALUES(NEW.barkoda1);
END//
DELIMITER ;
But same error happened, what am i doing wrong here?
You need a BEFORE INSERT TRIGGER
And then only use the SET Clause
DELIMITER //
CREATE TRIGGER pdfdeneme BEFORE INSERT
ON finyeb_ba_2369_bio_for_2__r_d_
FOR EACH ROW
BEGIN
SET NEW.`#pdfa1` = CONCAT(NEW.barkoda1,'.pdf');
END//
DELIMITER ;
But your column name is a bad choice, it leads on the first glance to false conclusions.
I am trying to set up a TRIGGER to clear empty strings before INSERT. Not rocket science but I can't find the error in my syntax!
Here is the TRIGGER itself
USE `ga_abtest_logging`;
DELIMITER $$
CREATE TRIGGER avoid_empty
BEFORE INSERT ON daily_analytics
FOR EACH ROW
BEGIN
IF profileID = ''
THEN SET profileID = NULL
END IF;
END$$
Here is what workbench is showing:
On hover over the END IF it reads syntax error, unexpected END, expecting ';'
Could I have a problem with the settings on my DB? I have gone through the MySQL docs and I think the trigger looks right! Does anyone see anything obviously wrong?
You should make a few changes:
Use the NEW. prefix when referencing a column value
Add a semi-colon at the end of the line where you set the value
For example:
DELIMITER $$
CREATE TRIGGER tr_b_ins_daily_analytics BEFORE INSERT ON daily_analytics FOR EACH ROW BEGIN
IF (NEW.profileID = '')
THEN
SET NEW.profileID = NULL;
END IF;
END $$
DELIMITER ;
The code below should work.
DELIMITER $$
CREATE TRIGGER avoid_empty
BEFORE INSERT ON daily_analytics
FOR EACH ROW
BEGIN
IF NEW.profileID = ''
THEN SET NEW.profileID = NULL;
END IF;
END;$$
DELIMITER ;
i have written a trigger in mysqlworkbench that should update the product stock after a new line had been added to the order table(my code is in dutch so thats why im explaining this) But it doesn't work, when i try to apply it mysqlworkbench says its sql code contains errors.
Here's the trigger:
CREATE DEFINER = CURRENT_USER TRIGGER `winkel`.`bestelregel_AFTER_INSERT` AFTER INSERT ON `bestelregel` FOR EACH ROW
BEGIN
if Product.productnr = NEW.productnr
then
Update Product
Set Hoeveelheid = (Hoeveelheid - NEW.aantal)
Where productnr = NEW.productnr;
end if;
END
What is Product in the if statement? That is, no doubt, generating a syntax error, because it is unrecognized.
I think you intend for the body to be simply:
Update Product p.
Set Hoeveelheid = (Hoeveelheid - NEW.aantal)
Where p.productnr = NEW.productnr;
The if irrelevant.
I would expect the full version to look something like:
DELIMITER $$
CREATE DEFINER = CURRENT_USER TRIGGER `winkel`.`bestelregel_AFTER_INSERT`
AFTER INSERT ON `bestelregel` FOR EACH ROW
BEGIN
UPDATE Product p
SET Hoeveelheid = (Hoeveelheid - NEW.aantal)
WHERE p.productnr = NEW.productnr;
END $$
DELIMITER ;
You have delimiter trouble. You need
DELIMITER $$
CREATE ..... TRIGGER ...
BEGIN
END$$
DELIMITER ;
I am trying to implement the following trigger but I am getting a MySQL syntax error. The idea is that after each time the table is updated I want to set the updated 'valid' field to 0 if the 'banned' field has been changed to 1. Also is the logic below correct?
Create Trigger `customers` Before Update on `customers` for each row BEGIN
set new.valid = 0 WHERE new.banned = 1;
END;
Yes the trigger should be something as
delimiter //
Create Trigger `customers_update`
Before Update on `customers`
for each row
BEGIN
IF new.banned = 1
THEN set new.valid = 0 ;
END IF ;
END;//
As you can see I have used delimiter in the trigger which is needed for the trigger. There is a nice explanation of this here What does DELIMITER // do in a Trigger?
Is it possible to declare that a column in MySQL should be unmodifiable once initially set? I have a column that has the following definition: created timestamp default current_timestamp and I'd like to make sure that nobody messes with it after my rows are created.
You can accomplish this using a BEFORE UPDATE trigger:
DELIMITER $$
CREATE TRIGGER trFoo BEFORE UPDATE ON foo
FOR EACH ROW BEGIN
IF NEW.Bar != OLD.Bar THEN
SET NEW.Bar = OLD.Bar;
END IF;
END$$
DELIMITER ;