我試圖做一個觸發器,但我得到了一個突變表錯誤。 SQL代碼是這樣的:Oracle SQL觸發器上的突變表
CREATE OR REPLACE TRIGGER CHK_Apartado_D
BEFORE INSERT OR UPDATE ON CONTRACTS
FOR EACH ROW
DECLARE
errorvisualizacion EXCEPTION;
local_enddate DATE;
BEGIN
SELECT enddate INTO local_enddate FROM CONTRACTS WHERE clientid=:new.clientid;
IF local_enddate > SYSDATE OR local_enddate IS NULL
THEN
UPDATE CONTRACTS SET enddate = SYSDATE - 1 WHERE clientid=:new.clientid;
END IF;
END CHK_Apartado_B;
/
而我得到的錯誤是這樣的:
Informe de error -
Error SQL: ORA-04091: table HR.CONTRACTS is mutating, trigger/function may not see it
ORA-06512: at "HR.CHK_APARTADO_D", line 5
ORA-04088: error during execution of trigger 'HR.CHK_APARTADO_D'
ORA-06512: at "HR.CHK_APARTADO_D", line 8
ORA-04088: error during execution of trigger 'HR.CHK_APARTADO_D'
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.
當我插入一個新的合同我要檢查,如果該客戶端在實際的其他合同日期,如果他有我必須更新結束日期contracte到昨天,讓新的INSERT。那麼,我該如何防止變異表呢?
這似乎是一個最近令人困惑的練習: [here](http://stackoverflow.com/q/43494370/266304),[here](http://stackoverflow.com/q/43483253/266304),[here](http://stackoverflow.com/ q /二十六萬六千三百○四分之四千三百二十三萬八千四百八十八);哦,去年的這個時候,[這裏](http://stackoverflow.com/q/36372988/266304),... –
@AlexPoole - 似乎我們需要一個規範的答案,只是繼續關閉重複。 – APC
@APC - 是一個規範的答案,將有效地作爲適當的分配答案,但?儘管我不確定我是否看到過任何地方的作業,暗示了分配者實際上在尋找什麼答案......或者至少不是答案,我會很樂意嘗試寫出* 8-) –