CODEWITHSUNDEEP
mysqlsqltriggers
trinny
trinny

Reputation: 232

trigger update on column change

Hello currently my trigger updates on table update, and I need to change this to only fire when specific column changes.

code: create trigger money after update on things

for each row
begin
UPDATE `current` c 
INNER JOIN things    t ON c.id2 = t.id2
INNER JOIN dude_base d ON d.id1 = c.is1
SET c.`curr_cash` = t.thing_cost * d.salary / 100;
end;
$$

And I need to change so it will turn on, when there is update on "thing_cost" from things.

@edit I have to update that curr_cash and things cost are totaly different values, I cannot compare them, they will always be different.

When I used 

if NEW.things_cost <> OLD.things_cost

I get following error:

#1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 10

@edit

create trigger wys_sk_b after update on `dude_base`
for each row
begin
if NEW.salary <> OLD.salary
then
UPDATE `current` s 
INNER JOIN things u ON s.id_thing = u.id_thing 
INNER JOIN dude_base b ON b.id = s.id
SET s.`curr_cash` = u.thing_cost * b.salary/ 100;
end if;
$$

Upvotes: 1

Views: 9943

Answers (2)

user3270575
user3270575

Reputation: 83

Try this code...

**create table sales** (orderno INT, sale INT,empsalary int, ts TIMESTAMP);

**create table history** (updated varchar(20), oldvalue INT,newvalue INT);

INSERT INTO **sales** (orderno,sale,empsalary) VALUES(1,700,7000);

INSERT INTO **sales** (orderno,sale,empsalary) VALUES(2,800,8000);

INSERT INTO **sales** (orderno,sale,empsalary) VALUES(3,900,9000);


DROP TRIGGER test.instrigger;

DELIMITER ///

CREATE TRIGGER test.instrigger AFTER UPDATE ON sales
FOR EACH ROW

BEGIN

    IF NEW.sale <> OLD.sale THEN  
        INSERT INTO history (updated, oldvalue, newvalue) VALUES('sale', OLD.sale,NEW.sale);

    END IF;
    IF NEW.empsalary <> OLD.empsalary THEN  
        INSERT INTO history (updated, oldvalue, newvalue) VALUES('empsalary', OLD.empsalary,NEW.empsalary);
    END IF;
END;

///

DELIMITER ;

Upvotes: 3

juergen d
juergen d

Reputation: 204894

delimiter $$
create trigger wys_sk_b after update on `dude_base`
for each row
begin
  if NEW.salary <> OLD.salary
  then
    UPDATE `current` s 
    INNER JOIN things u ON s.id_thing = u.id_thing 
    INNER JOIN dude_base b ON b.id = s.id
    SET s.`curr_cash` = u.thing_cost * b.salary/ 100;
  end if;
end;
$$

Upvotes: 3

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