使用過濾器觸發器

Question

在Oracle 12c上，我需要使用過濾器創建觸發器。我的過濾器是：

WHEN PERIOD <> FN_PERIODNEXT 

其中FN_PERIODNEXT是一個函數。

以下是觸發器的代碼。

CREATE OR REPLACE TRIGGER AFTERIUDLIQUIDATIONSDETAILS 
    BEFORE INSERT OR DELETE 
    ON LIQUIDATIONSDETAILS 
    FOR EACH ROW 
    WHEN (NEW.PERIODID <> FN_PERIODNEXT) 
BEGIN 
    IF INSERTING 
    THEN 
     UPDATE APPOINTSOFCAS 
     SET INLD = INLD + 1 
     WHERE  CUSTOMERID = :NEW.CUSTOMERID 
      AND ID = :NEW.APPOINTOFCAID 
      AND KINDCONTROLID = :NEW.KINDCONTROLID; 
    END IF; 

    IF DELETING 
    THEN 
     UPDATE APPOINTSOFCAS 
     SET INLD = INLD - 1 
     WHERE  CUSTOMERID = :OLD.CUSTOMERID 
      AND ID = :OLD.APPOINTOFCAID 
      AND KINDCONTROLID = :OLD.KINDCONTROLID; 
    END IF; 
END; 
/

這編譯失敗，具有：

[Error] Compilation (8: 26): ORA-04076: invalid NEW or OLD specification 

Answer 1

的WHEN子句是Boolean表達式由Oracle執行該觸發器的身體前評估。你需要改變這一行，因爲它的語法問題，因此不編譯。

WHEN (NEW.PERIOD <> OLD.FN_PERIODNEXT) 

現在考慮的事實，你FN_PERIODNEXT是Function，那麼上面的語句將not work。上述statememt評估僅適用於表格列。

在你的情況，你需要你的觸發作爲體內處理這種情況：

If FN_PERIODNEXT <> :NEW.PERIOD then 
. . 
.. 
.. 
End if; 

所以，你的觸發變得像：

CREATE OR REPLACE TRIGGER AFTERIUDLIQUIDATIONSDETAILS 
    BEFORE INSERT OR DELETE 
    ON LIQUIDATIONSDETAILS 
    FOR EACH ROW 
    --WHEN (NEW.PERIODID <> FN_PERIODNEXT) 
BEGIN 
If FN_PERIODNEXT <> :NEW.PERIOD 
    then 

    IF INSERTING 
    THEN 
     UPDATE APPOINTSOFCAS 
     SET INLD = INLD + 1 
     WHERE  CUSTOMERID = :NEW.CUSTOMERID 
      AND ID = :NEW.APPOINTOFCAID 
      AND KINDCONTROLID = :NEW.KINDCONTROLID; 
    END IF; 

    IF DELETING 
    THEN 
     UPDATE APPOINTSOFCAS 
     SET INLD = INLD - 1 
     WHERE  CUSTOMERID = :OLD.CUSTOMERID 
      AND ID = :OLD.APPOINTOFCAID 
      AND KINDCONTROLID = :OLD.KINDCONTROLID; 
    END IF; 
END IF; 
END; 
/