I have created a basic trigger that checks if the the new value inserted into a row is greater or equal than 1 and less or equal than 10 , this is for just test qualifications , the thing is that wherever I just insert a new test qualification for example 0 it adds it up to the table, but my trigger checks that this value should be greater than 0 and is not working
Trigger that checks if a qualification is greater or equal than 1 or less or equal than 10
delimiter //
CREATE TRIGGER checkQlfy BEFORE
INSERT ON qualify
FOR EACH ROW
BEGIN
IF new.qualify_pp >= 1 and new.qualify_pp <= 10 THEN
INSERT INTO qualify(qualify_pp) VALUES (new.qualify_pp);
END IF;
END//
delimiter ;
Now, this trigger is created succefully but wherever I insert a new value lets say with this line
INSERT INTO qualify(qualify_pp) VALUES(0);
It is inserted into the table, but I have said in the trigger that values greater or equal than 1 should be added.
I dont know why is this happening.
You have two options:
Add a CHECK constraint over the qualify_pp field. Only works in versions >= 8.0.16 (here's why).
You cannot change the insert operation triggering the trigger. You can, however, raise an error if a validation fails so the insert is not performed.
E.g. (see how the validations in the IF changed):
delimiter //
CREATE TRIGGER checkQlfy BEFORE
INSERT ON qualify
FOR EACH ROW
BEGIN
IF new.qualify_pp < 1 OR new.qualify_pp > 10 THEN
SIGNAL SQLSTATE '45000' SET MESSAGE_TEXT = 'Not allowed / some message';
END IF;
END//
delimiter ;
The trigger you have written would do the insert based on:
1) insert statement and trigger insert if 1<=value<=10
2) insert statement and trigger not insert if 1>=value>=10
You would have to add a check constraint in it, rather than having a trigger!
Related
I need to create a Trigger that checks BEFORE INSERT. For each row, if pc.price <= 0 then the price should be set to its absolute value
CREATE TRIGGER Neg_PC_Price
BEFORE INSERT ON PC
FOR EACH ROW
BEGIN
IF NEW.price <= 0
THEN ABS(NEW.price)
END IF;
END;
This is what I pieced together from a different solution but instead of setting the new price they returned an error statement and not sure how to input with the updated positive price.
I do not see the reason in additional and obviously excess IF statement. Simply
CREATE TRIGGER Neg_PC_Price
BEFORE INSERT ON PC
FOR EACH ROW
SET NEW.price = ABS(NEW.price);
I have a table with 2 columns named "Table1":
(Column 1 named "Col1" with the values: A,B,C,D,E,F)
(Column 2 named "Col2" with the values: 12,15,2,5,200,1).
I would like get all the values from column 2 to change to the value 1 if their value is lower than 100, so that column 2 will eventually look like this:
(Column 2 named "Col2" with the values: 1,1,1,1,200,1).
I tried to create a trigger:
delimiter //
CREATE TRIGGER Table1upd BEFORE UPDATE ON Table1
FOR EACH ROW
BEGIN
IF NEW.Col2<100 THEN
SET NEW.Col2=1;
END IF;
END;//
delimiter ;
When creating the trigger in MySQL workbench it says that the trigger was added but that 0 row(s) affected.
I assume my problem is with the BEFORE UPDATE choice, because the trigger does work when I update a value in the table, but I don't know what to change it to so that the trigger will also initially execute automatically when I create it.
Thank you in advance for any help,
D
The answer is simple: a BEFORE UPDATE trigger only triggers on UPDATE, so you need a second trigger BEFORE INSERT to cover both use cases: update and insert:
delimiter //
CREATE TRIGGER Table1insert BEFORE INSERT ON Table1
FOR EACH ROW
BEGIN
IF NEW.Col2<100 THEN
SET NEW.Col2=1;
END IF;
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)