mysql create trigger ON INSERT - mysql

Suppose I have the following table
create table try ( name varchar(10), username varchar(10))
Is it possible to have a trigger 'ON INSERT' to set username=user() ?
I tried doing
create trigger userIns ON INSERT on try for each row set new.username=user();
but this gives some syntax error
I have seen documentation about BEFORE INSERT,AFTER INSERT. How about ON INSERT?
if not, whats my best bet?

The syntax is :
CREATE TRIGGER trigger_name trigger_time trigger_event
ON table_name
FOR EACH ROW
BEGIN
...
END
Your syntax is wrong in trigger_time part.
Trigger activation time can be BEFORE or AFTER. You must specify the
activation time when you define a trigger. You use BEFORE keyword if
you want to process action prior to the change is made on the table
and AFTER if you need to process action after change are made.
Try this :
create trigger userIns BEFORE INSERT on try for each row set new.username=user();
More : MYSQL Trigger Tutorial

Correct Syntax is
Create Trigger trigger_name trigger_time trigger_event
on table_name
for each row
begin
....
end
Trigger_time => Before | After
trigger_event => Insert | Update | Delete
Please check
create trigger userIns INSERT on try for each row begin set new.username=user() end;

None of the above was my problem. I was really looking for an ON INSERT trigger - but it does not exist in MYSQL. So I used BEFORE INSERT and that works fine
create trigger userIns BEFORE INSERT on try for each row set new.CREATED_BY=user();

The problem is you need to set the delimiter to something other than ';' before you begin the trigger code. Put the new delimiter after 'end' and then change the delimiter back to ';' after you are done.

Related

MYSQL fires the trigger only when no value manually inserted - not working

Hi I just need help as I am just new to mysql trigger.
I'm trying to create a trigger that if the project id is NULL then it will set it to new value but if someone has manually insert a value then it won't do anything.
I performed this but it ain't working on mysql.
CREATE TRIGGER custom_autonums_pdl BEFORE INSERT ON project_details_logs
FOR each ROW
WHEN (new.projectid IS NULL)
BEGIN
SET new.projectid = getNextCustomSeqPl(year(now()),year(now()));
END//
delimiter ;
If someone can direct me to correct this, appreciate it.
Thank you.
I haven't seen a MariaDb/MySQL trigger that uses the WHEN syntax available in other major RDBMS - you'd need to run the trigger for every insert and conditionally act on the id:
DELIMITER |
CREATE TRIGGER custom_autonums_pdl
BEFORE INSERT ON project_details_logs
FOR each ROW
BEGIN
IF new.projectid IS NULL THEN
SET new.projectid = getNextCustomSeqPl(year(now()),year(now()));
END IF;
END|
DELIMITER ;

Make a trigger that copies new data from table to another table after insert

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.

MySQL trigger not working. What could be the issue?

I need to update an existing table after insert on another table. This is what I have.
DELIMITER $$
CREATE TRIGGER `some_trigger`
AFTER INSERT ON `old_table`
FOR EACH ROW BEGIN
UPDATE `new_table` set `some_column` = new.`column`
WHERE `new_table`.id = new.id
END $$
DELIMITER;
Trigger definition successfully executed and trigger exists with
SQL_MODE - NO_ENGINE_SUBSTITUTION
DEFINER - root#%
Is there something horribly wrong with this?
Can you please confirm that the new.id i.e the id generated on old_table insertion is also present in the new table ?
Because the possible reason could be that in new table new.id is not present at the time on old_table insertion.

Using MySQL Database Triggers

I have three tables: users, account and accountinfo and I am trying to make a trigger that will add the id from users to the UserID column in the account table. Here is what I tried:
CREATE TRIGGER catchUser BEFORE INSERT ON defaultdatabase.users
FOR EACH ROW
BEGIN
INSERT INTO defaultdatabase.account(UserID) VALUES (new.id);
END
However, I get an error right after my INSERT statement that says,
Syntax Error: insert 'semicolon'
Why am I getting this error is I have the semicolon or is my trigger just wrong?
I'm using MySQL 5.6 if that makes any difference as well.
You need to specify the delimiter:
delimiter //
CREATE TRIGGER catchUser BEFORE INSERT ON defaultdatabase.users
FOR EACH ROW
BEGIN
INSERT INTO defaultdatabase.account(UserID) VALUES (new.id);
END; //
delimiter ;
Try this:
CREATE TRIGGER catchUser BEFORE INSERT ON defaultdatabase.users
FOR EACH ROW
BEGIN
INSERT INTO defaultdatabase.account(UserID) VALUES (new.id)
END;
Please insert a semicolon after END.

Creating Last Modified SQL Trigger

I am trying to create a trigger to update last_modified field when the row is updated.
This is what i have tried:
USE `mydb`;
DELIMITER $$
DROP TRIGGER IF EXISTS mydb.products_AUPD$$
USE `mydb`$$
CREATE TRIGGER `products_AUPD` AFTER UPDATE ON products
FOR EACH ROW BEGIN
SET NEW.`last_modified` = NOW();
END;
$$
DELIMITER ;
The problem is MySQL workbench wont let me save it (I'm assuming that there is something wrong with it but i can't find out what)
Turns out the version of MySQL Workbench I was using(6.0xxx) had a bug in it which played havoc with triggers. I updated to 6.2xxx.
That was the first problem.
The second problem was that i was using the NEW keyword in an AFTER trigger which is not allowed:
Within the trigger body, you can refer to columns in the subject table
(the table associated with the trigger) by using the aliases OLD and
NEW. OLD.col_name refers to a column of an existing row before it is
updated or deleted. NEW.col_name refers to the column of a new row to
be inserted or an existing row after it is updated.
So my new trigger looks like this:
CREATE DEFINER = CURRENT_USER TRIGGER `mydb`.`products_BEFORE_UPDATE` BEFORE UPDATE ON `products` FOR EACH ROW
BEGIN
SET NEW.`last_modified` = NOW();
END;
Notice there is no USE or DELIMITER statement? That is because the new version of MySQL Workbench puts this in for you (including the end delimiter $$):
USE `mydb`;
DELIMITER $$
USE `mydb`$$
DROP TRIGGER IF EXISTS `mydb`.`products_BEFORE_INSERT` $$
USE `mydb`$$
CREATE DEFINER = CURRENT_USER TRIGGER `mydb`.`products_BEFORE_INSERT` BEFORE INSERT ON `products` FOR EACH ROW
BEGIN
SET NEW.`last_modified` = NOW();
END;$$