Problems creating TRIGGER in MySQL - mysql

I am first time using trigger concept in my MYSQL workbench like below query,
First I created people table by using below query,
CREATE TABLE people (age INT, name varchar(150));
Then I used below query for trigger
DELIMITER
CREATE TRIGGER agecheck BEFORE INSERT ON raptor1_5.people FOR EACH ROW IF NEW.age < 0 THEN SET NEW.age = 0; END IF;
DELIMITER ;
But agecheck trigger not creating to people table. Its does not show any error message when I run this query.
Here is my table images,
Updated : based on the answer

Try with this.
USE `raptor1_5`;
DELIMITER $$
DROP TRIGGER IF EXISTS raptor1_5.agecheck$$
USE `raptor1_5`$$
CREATE TRIGGER agecheck BEFORE INSERT ON people
FOR EACH ROW
BEGIN
IF NEW.age < 0 THEN
SET NEW.age = 0;
END IF;
END$$
DELIMITER ;

The standard trigger syntax should be as
DELIMITER //
CREATE TRIGGER agecheck BEFORE INSERT ON raptor1_5.people
FOR EACH ROW
BEGIN
IF NEW.age < 0 THEN
SET NEW.age = 0;
END IF;
END;//
DELIMITER ;
The above is when you run on mysql cli, however in phpmyadmin or workbench check if you have an option to set the delimiter if yes choose that and remove the delimiter part from the above.

Related

MySQL Trigger Is Not Inserting Date/Time String Into Column

Here's my trigger. Updating a row in event does not set a date/time string in sf_timestamp. New to triggers so I am not sure how to debug.
DELIMITER $$
CREATE DEFINER = `root`#`localhost` TRIGGER `event_stamp`
BEFORE UPDATE ON `event`
FOR EACH ROW
BEGIN
SET NEW.sf_timestamp = DATE_FORMAT(NOW(),'%Y-%m-%d %T');
END;;
DELIMITER $$
Suggestions?
When you define a DELIMITER, you need to keep that same delimiter until you are done with the block you are trying to declare. In this case, you are trying to create a new trigger and you need MySQL to interpret the whole block with multiple lines as one and ending them with the default ;
But when you are done, you have to END the block with the DELIMITER you have set earlier as following:
DELIMITER $$
CREATE DEFINER = `root`#`localhost` TRIGGER `event_stamp`
BEFORE UPDATE ON `event`
FOR EACH ROW
BEGIN
SET NEW.sf_timestamp = DATE_FORMAT(NOW(),'%Y-%m-%d %T');
END$$
DELIMITER ;
Unless your update statement includes a value for sf_timestamp, that field likely doesn't have a value to be formatted. If you are attempting to update the timestamp to represent the time when the record is updated, why not just use the current time?
DELIMITER $$
CREATE DEFINER = `root`#`localhost` TRIGGER `event_stamp` BEFORE UPDATE ON `event`
FOR EACH ROW
BEGIN
SET NEW.sf_timestamp = now();
END;;
DELIMITER $$
DELIMITER $$
CREATE DEFINER = `root`#`localhost` TRIGGER `event_stamp`
BEFORE UPDATE ON `event`
FOR EACH ROW
BEGIN
SET NEW.sf_timestamp = DATE_FORMAT(NOW(),'%Y-%m-%d %T');
END$$
DELIMITER ;
Followed #pensums suggestion and this worked for me

CREATE TRIGGER to monitor a specific table row

I have two tables & need to write a TRIGGER for this scenario.
1. Parameters_Table(int pkid, string param_name, string param_value)
2. Tokens_Table(int pkid,string item,string validity)
I have a requirement of deleting all entries in Tokens_Table if a particular row where param_name='Enterprise' in Parameters_Table changes its 'param_value'. The value is changed from UI. eg., row <7,enterprise,60> changes to <7,enterprise,25> in Parameters_Table then delete all entries from Tokens_Table.
How should I write the trigger. Please guide. (I need to write this for Informix Database, but mysql queries would also help)
DELIMITER $$
CREATE TRIGGER after_update AFTER UPDATE ON Parameters_Table
FOR EACH ROW
BEGIN
IF OLD.param_name ='Enterprise' THEN
IF NEW.param_value != OLD.param_value THEN
DELETE FROM Tokens_Table WHERE pkid = NEW.pkid;
END IF;
END IF;
END$$
Just try above code.Hope this will helps.
You can try the following syntax/format:
DELIMITER $$
CREATE TRIGGER delete_tokens AFTER INSERT ON Parameters_Table
FOR EACH ROW
BEGIN
IF NEW.param_name = 'enterprise' THEN
BEGIN
DELETE FROM Tokens_Table WHERE pkid = NEW.pkid;
END;
END IF;
END$$

MySQL Trigger Not Compiling and logic

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?

Trigger not checking if condition

I have created a trigger , and this trigger updating the field value , but not checking the if condition ,
DELIMITER $$
create trigger `njsystem`.`test` BEFORE UPDATE on `njsystem`.`tbl_users`
for each row
BEGIN
IF (NEW.user_failed_logins > 3) THEN
UPDATE tbl_users SET user_active = 0;
END IF;
END; $$
DELIMITER ;
What I understand from your problem statement is that, you wanted to set user_active to 0 if user_failed_logins count goes above 3. Here is solution for that, you can also change values using new.
DELIMITER $$
create trigger `test` BEFORE UPDATE on `tbl_users`
for each row
BEGIN
IF (NEW.user_failed_logins > 3) THEN
SET NEW.user_active = 0;
END IF;
END; $$
DELIMITER ;

MYSQL trigger error 1064

I would like to check if a record is being created with a user id, if not then generate one. I can't figure out what I'm doing wrong?
delimiter $$
DROP TRIGGER IF EXISTS init_uuid_users;
CREATE TRIGGER init_uuid_users BEFORE INSERT ON `users`
FOR EACH ROW BEGIN
IF (NEW.username IS NULL) THEN
SET NEW.username = UUID();
END IF;
END;
$$
delimiter ;
DROP TRIGGER IF EXISTS init_uuid_users;
put it before delimiter.
And remove ; after END.