Question

如果插入或更新了行BLOCKED = 0：

，我会触发删除数据

create  or replace  trigger DATA_SOURCE_delete_blocked
after insert or update
on DATA_SOURCE
FOR EACH ROW
WHEN (new.BLOCKED=0)
BEGIN
  DELETE FROM DATA_SOURCE WHERE DATA_SOURCE_ID=:NEW.DATA_SOURCE_ID;
end;

它适用于插入（至少数据没有写入，但可能有错误），但是对于更新，它不会因为变异错误而起作用：

04091. 00000 -  "table %s.%s is mutating, trigger/function may not see it"
*Cause:    A trigger (or a user defined plsql function that is referenced in
           this statement) attempted to look at (or modify) a table that was
           in the middle of being modified by the statement which fired it.
*Action:   Rewrite the trigger (or function) so it does not read that table.

在插入/更新后是否有任何简单的方法可以在创建视图时删除行？

更新：解决了compaund触发器的问题：

CREATE  OR REPLACE  TRIGGER DATA_SOURCE_DELETE_BLOCKED
FOR INSERT OR UPDATE ON DATA_SOURCE when (new.BLOCKED=0)
COMPOUND TRIGGER
ID1 NUMBER;
AFTER EACH ROW IS
BEGIN
  ID1:=:NEW.DATA_SOURCE_ID;
END AFTER EACH ROW;
AFTER STATEMENT IS
BEGIN
   DELETE FROM DATA_SOURCE WHERE DATA_SOURCE_ID=ID1;
END AFTER STATEMENT;
END DATA_SOURCE_DELETE_BLOCKED;

更新后触发删除列

0 个答案: