There are 12 types of triggers in PL/SQL that contains the combination of BEFORE, AFTER, ROW Level, TABLE Level, INSERT, UPDATE, DELETE, ALL, and Instead of keywords. Structure: CREATE [OR REPLACE] TRIGGER trigger_name {BEFORE | AFTER | INSTEAD OF} {INSERT [OR] | UPDATE [OR] | DELETE} [OF col_name] [ON table_name] [REFERENCING OLD AS old NEW AS new] [FOR EACH ROW] WHEN (condition)