how to get value from select query in trigger in mysql5?

Question

How to get value from select query in trigger and insert that value in table?

Answer 1

For an INSERT Trigger query you would use the object NEW
For an UPDATE Trigger query you would use the object OLD and NEW
For a DELETE Trigger query you would use the object OLD

Example 1 : iF you ran INSERT INTO mytable (num) VALUES (10);
In the INSERT trigger, you reference the column as NEW.num (10);

Example 2 : iF you ran UPDATE mytable SET num = 41 WHERE num = 10;
In the UPDATE trigger, you reference OLD.num (10) and NEW.num (41)

Example 3 : iF you ran DELETE mytable num = 104;
In the DELETE trigger, you reference OLD.num (104)

Use something like this:

DELIMITER $$

create trigger my_trigger
AFTER UPDATE on my_update_table
for each row
begin

    DECLARE P1,P2 VARCHAR(50);

    SELECT PRICENAME INTO P1 FROM PRICEIES WHERE PRICEID=OLD.PRICEID;
    SELECT PRICENAME INTO P2 FROM PRICEIES WHERE PRICEID=NEW.PRICEID;
    INSERT INTO AUDITLOG(OLDVALUE, NEWVALUE) VALUES (P1,P2);

end $$

DELIMITER ;