:Old and :New value in pl sql triggers HD

A plsql tutorial about how to reference old and new column value of a table using :old or :new and how they are related to insert, update or delete dml transaction. Go through this oracle tutorial which will give you the concept about how to use :old and :new references. Here is the trigger example. create or replace trigger trigger_name before insert or update or delete on table_name for each row begin if inserting then dbms_output.put_line("Before inserting Old value is "||:old.column_name||" New value : "||