Il trigger INSTEAD OF sarebbe simile a questo (presumo che tu abbia una colonna di chiave primaria id ):
SQL> CREATE OR REPLACE TRIGGER trg_staff_data_cpt_instead_upd
2 INSTEAD OF UPDATE ON staff_data_compat
3 FOR EACH ROW
4 BEGIN
5 UPDATE staff_data_compat_t
6 SET knownas_surname = :new.surname,
7 first_name = :new.first_name,
8 middle_name = :new.mid_name
9 WHERE id = :new.id
10 END;
11 /
Trigger created
Si noti che alcune colonne potrebbero infatti essere aggiornabili nella vista originale. Interroga all_updatable_columns visualizza (prima di creare il trigger) per scoprire:
SQL> CREATE TABLE staff_data_compat_t AS
2 SELECT object_name knownas_surname,
3 owner surname,
4 object_type first_name,
5 subobject_name middle_name
6 FROM all_objects;
Table created
SQL> CREATE OR REPLACE VIEW staff_data_compat AS
2 SELECT
3 NVL(knownas_surname,surname) as surname,
4 first_name,
5 middle_name mid_name,
6 NULL as ni,
7 NULL as home_tel_no
8 FROM staff_data_compat_t;
Visualizza creato
SQL> SELECT * FROM all_updatable_columns WHERE table_name = 'STAFF_DATA_COMPAT';
OWNER TABLE_NAME COLUMN_NAME UPDATABLE INSERTABLE DELETABLE
------ ------------------ ------------ --------- ---------- ---------
VNZ STAFF_DATA_COMPAT SURNAME NO NO NO
VNZ STAFF_DATA_COMPAT FIRST_NAME YES YES YES
VNZ STAFF_DATA_COMPAT MID_NAME YES YES YES
VNZ STAFF_DATA_COMPAT NI NO NO NO
VNZ STAFF_DATA_COMPAT HOME_TEL_NO NO NO NO
Se devi solo inserire/aggiornare queste colonne, non hai bisogno di un trigger INSTEAD OF.
