Sql 消费。你的意思是DECLARE@p_mnozstvi INTEGER=（从deleted中选择Count（množstvíSklad）？你的触发器假设DELETE包含一行（DECLARE@pžmnozstvi INTEGER=（从deleted中选择mno

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消费。你的意思是

DECLARE@p_mnozstvi INTEGER=（从deleted中选择Count（množstvíSklad）

？你的触发器假设

DELETE

包含一行（

DECLARE@pžmnozstvi INTEGER=（从deleted中选择množstvíSklad）

），它不应该这样做。一个

DELETE

可以包含一行或多行，并且对于单个DML操作触发一次触发器（不是每行触发一次）。因此，如果

DELETE

包含多行，则对象

deleted

也将包含多行，突出显示的SQL将失败。行

DELETE FROM ZbožíWHERE（SELECT ZbožíID FROM deleted）=ZbožID

也做出了相同的假设。

DELETE FROM Zboží WHERE (SELECT zbožíID FROM deleted) = zbožíID 

DELETE FROM Zboží WHERE zbožíID IN (SELECT zbožíID FROM deleted)

DECLARE @p_mnozstvi INTEGER;
SELECT @p_mnozstvi = množstvíSklad FROM deleted;

CREATE TRIGGER zkontrolujMnožství ON Zboží INSTEAD OF DELETE
AS BEGIN 
    DECLARE @p_mnozstvi INTEGER;
    DECLARE d_cursor CURSOR FOR
        SELECT množstvíSklad FROM deleted;

    OPEN d_cursor;
    FETCH NEXT FROM d_cursor INTO @p_mnozstvi;

    WHILE @@FETCH_STATUS = 0  
    BEGIN  
        IF @p_mnozstvi < 0 -- Try to know if is empty 
            EXECUTE vyvolej_chybu_sp 15; -- Raise error
        ELSE 
            DELETE FROM Zboží WHERE zbožíID IN (SELECT zbožíID FROM deleted);
    END;
    CLOSE db_cursor; 
    DEALLOCATE db_cursor;
END;

CREATE TRIGGER zkontrolujMnožství ON Zboží INSTEAD OF DELETE
AS BEGIN     
    IF (EXISTS (SELECT 1 FROM deleted WHERE množstvíSklad < 0)
        EXECUTE vyvolej_chybu_sp 15; -- Raise error
    ELSE 
        DELETE FROM Zboží
            WHERE zbožíID IN (SELECT zbožíID FROM deleted);
END;