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

:New and :Old Value can be differentiated in DML Statements .
Insert -- :Old = NULL :New= Inserted new value

Update -- :Old = Value present in table before the Update statement Triggered :New = Given new value to Update

Delete -- :Old = Value before deletion :New = NULL