我的触发器不会工作

Question

我一直在为我的SQL数据库开发一个触发器。

的表格：

TABLE1：ID（INT，自动增量），值1（VARCHAR），值2（VARCHAR），计数（INT）

TABLE1_History：ID（从TABLE1.ID独立，INT，自动增量），相同的列TABLE1但具有添加的时间戳（SMALLDATETIME）

的代码：

SELECT @@ROWCOUNT FROM TABLE1_History, INSERTED 
    WHERE TABLE1_History.value1 LIKE INSERTED.value1 
    AND TABLE1_History.value2 LIKE INSERTED.value2 
    AND DATEDIFF(HOUR,TABLE1_History."TimeStamp", GETDATE()) > 24; 

    IF(@@ROWCOUNT = 0) 
    BEGIN 
     INSERT INTO TABLE1_History(value1, value2, count, "TimeStamp") 
     SELECT value1, value2, count, GETDATE() FROM INSERTED 
    END 
    ELSE 
    BEGIN 
     UPDATE TABLE1_History 
     SET "TimeStamp" = GETDATE(), count = count+(SELECT count FROM INSERTED) 
     WHERE TABLE1_History.value1 LIKE (SELECT value1 FROM INSERTED) 
     AND TABLE1_History.value2 LIKE (SELECT value2 FROM INSERTED) 
     AND DATEDIFF(HOUR,TABLE1_History."TimeStamp", GETDATE()) < 24; 
    END 
END 

什么是应该发生的：

当我添加一个新行TABLE1我想TABLE1_History更新。

TABLE1_History ONLY中添加新行如果行已经用相同的值1 &值2作为新行和存在，如果它已经24h以上，因为加入该行。

否则，计数器增加。

会发生什么：

截至目前：TABLE1_History得到每一次更新。如果值匹配或不匹配，则无关紧要。

在我决定让TABLE1_History.ID与TABLE1.ID分开之前，它似乎工作正常。

Answer 1

你应该避免使用关键字TimeStamp。如果你可以把它改成LastModified什么

不使用@@ROWCOUNT，你可以加入INSERTED，我不知道为什么你正在使用LIKE。试试这个

IF NOT(EXISTS ( -- if it's not already in the table 
    SELECT value1 FROM TABLE1_History 
    JOIN INSERTED ON TABLE1_History.value1 = INSERTED.value1 
       AND TABLE1_History.value2 = INSERTED.value2 
    )) 
    OR EXISTS ( -- or its history was last modified over 24 hours ago 
    SELECT value1 FROM TABLE1_History 
    JOIN INSERTED ON TABLE1_History.value1 = INSERTED.value1 
       AND TABLE1_History.value2 = INSERTED.value2 
       AND DATEDIFF(HOUR,TABLE1_History."TimeStamp", GETDATE()) > 24 
    )  
BEGIN    -- insert it into the history table 
    INSERT INTO TABLE1_History(value1, value2, count, "TimeStamp") 
    SELECT value1, value2, count, GETDATE() FROM INSERTED 
END 
ELSE 
BEGIN    -- otherwise update the current history record 
    UPDATE th 
    SET th."TimeStamp" = GETDATE() 
     , th.count = th.count + INSERTED.count 
    FROM TABLE1_History th 
    JOIN INSERTED ON th.value1 = INSERTED.value1 
       AND th.value2 = INSERTED.value2 
       AND DATEDIFF(HOUR, th."TimeStamp", GETDATE()) < 24; 
END