Add, delete, modify, and query this table in oracle triggers

Add, delete, modify, and query this table in the oracle trigger (1) only the before insert trigger can query or update this table.

Create or replace trigger tri_test_ins before inserton testfor each rowdeclare v_cnt integer; begin select count (*) into v_cnt from test; dbms_output.put_line ('test count: '| to_char (v_cnt )); update test set a9 = '99'; end;

 

After insert is executed, only the currently inserted record value is not 99, and all other records are updated to 99. (2) before/after update, before/after delete, and after insert5 cannot be queried or updated. (3) using autonomous transactions can implement any trigger to query the table. However, this table cannot be updated in autonomous transactions. This table is the most common query condition.

Create or replace trigger tri_test_insafter updateon testfor each rowdeclare v_cnt integer; PRAGMA AUTONOMOUS_TRANSACTION; begin select count (*) into v_cnt from test; dbms_output.put_line (test count: '| to_char (v_cnt); end;

 

(4) use an autonomous transaction to add or delete records of the table. This is generally not used.