CREATE [OR REPLACE ] TRIGGER trigger_name  

{BEFORE | AFTER | INSTEAD OF }  

{INSERT [OR] | UPDATE [OR] | DELETE}  

[OF col_name]  

ON table_name  

[REFERENCING OLD AS o NEW AS n]  

[FOR EACH ROW]  

WHEN (condition)   

DECLARE 

   Declaration-statements 

BEGIN  

   Executable-statements 

EXCEPTION 

   Exception-handling-statements 

END;