Use of alternative triggers

When you need to create a trigger for a view to process business logic or data flows, you can use an alternative trigger to perform operations on view-related tables.

SQL> Create Table user_info (ID number, name varchar2 (200); table created. SQL> insert into user_info values (1, 'dinya '); 1 row created. SQL> commit; Commit complete. SQL> Create Table skill (ID number, skill varchar2 (300), user_id number); table created. SQL> insert into skill values (1, 'type', 1); 1 row created. SQL> commit; Commit complete. SQL> Create or replace view user_skills as select. ID,. name, B. skill from user_info A, skill B where. id = B. user_id; view created. SQL> select * From user_skills; ID name skill --------------- -------------------------------- when 1 dinya typed SQL> Update user_skills t set T. skill = 'Surfing the net'; update user_skills t set T. skill = 'internet' * error at line 1: ORA-01779: cannot modify a column which maps to a non key-preserved table SQL> Create or replace trigger user_skills_update 2 instead of update on user_skills 3 for each row 4 Begin 5 update skill set skill =: new. skill where user_id =: Old. ID; 6 end; 7/trigger created. SQL> Update user_skills t set T. skill = 'Surfing net' where T. id = 1; 1 row updated. SQL> commit; Commit complete. SQL> select * From skill; Id skill user_id ----------------- ----------------------------------------------------------------------- 1 SQL> # dinya