CREATE [OR REPLACE] TRIGGER [schema .] trigger 
{ BEFORE | AFTER | INSTEAD OF }
{ dml_event_clause 
| { ddl_event [OR ddl_event]...
  | database_event [OR database_event]...
  } 
  ON { [schema .] SCHEMA | DATABASE }
}
[WHEN ( condition ) ] 
{ pl/sql_block | call_procedure_statement }