PLSQL :NEW and :OLD

Question

Can anyone help me understand when to use :NEW and :OLD in PLSQL blocks, I\'m finding it very difficult to understand their usage.

Answer 1

:OLD and :NEW are variables of type Record and is identical in columns to the table row on which the trigger is fired. They are only available for row level triggers. Since triggers are fired on a predefined event automatically so :OLD and :NEW also get their value automatically . As the name suggests , :OLD will have the complete row values existing in table ( i.e has the existing values in case of update and delete ) and :NEW will have new values for that rows ( i.e. has the row value in case of update and insert ).