Create Or Replace Trigger tr_tttAfter Insert Or DeleteOn friendsFor Each RowBeginIf inserting Then
Insert Into friends (myid,friendid) Values (:New.friendid,:New.myid);End If;If deleting Then
Delete From friends Where myid=:Old.friendid And friendid=:Old.myid;End If;End;以上，希望对你有所帮助
