Question

我在下面有一个查询尝试更新数据库的记录。我无法运行它并显示错误：

Msg 147，Level 15，State 1，Line 12
聚合可能不会出现在WHERE子句中，除非它位于子查询
中

更改2018年1月报告故障超过6次的所有自行车的状态，并将自行车状态设置为＆＃34; C＆＃34;。

更新了我的SQL命令：

UPDATE Bike 
SET Status = 'C'
SELECT b.Status 
FROM Bike b
INNER JOIN Fault ft ON b.BikeID = ft.BikeID
INNER JOIN Feedback fb ON ft.FBID = fb.FBID
WHERE ((COUNT(fb.FBID) > 6) 
  AND (DATEPART(YEAR, fb.FbDateTIME) = 2018)
  AND (DATENAME(MONTH, fb.FbDateTIME) = 'January'))

包含在HAVING子句或选择列表中，正在聚合的列是外部引用。

由于我是SQL的新手，我不确定如何使子查询等效于此，并且任何人都可以帮助我吗？任何指导将不胜感激。

Answer 1

您不能在Aggregate子句中使用Where函数。您需要使用Having子句来过滤组。试试这样的事情

UPDATE b
SET    Status = 'C'
FROM   Bike b
WHERE  EXISTS (SELECT 1
               FROM   Fault ft
                      INNER JOIN Feedback fb
                              ON ft.FBID = fb.FBID
               WHERE  b.BikeID = ft.BikeID
                      AND fb.FbDateTIME >= '2018-01-01'
                      AND fb.FbDateTIME < '2018-02-01'
               HAVING Count(fb.FBID) > 6)

注意：要过滤Jan 2018条记录，我更喜欢使用此fb.FbDateTIME >= '2018-01-01' AND fb.FbDateTIME < '2018-02-01'方法。在DATEPART子句中使用Where函数将使查询不可搜索

Answer 2

将COUNT（1）移至

UPDATE B
SET Status = 'C'
FROM Bike b
INNER JOIN Fault ft ON b.BikeID = ft.BikeID
INNER JOIN Feedback fb ON ft.FBID = fb.FBID
WHERE (
  AND (DATEPART(YEAR, fb.FbDateTIME) = 2018)
  AND (DATENAME(MONTH, fb.FbDateTIME) = 'January'))
HAVING (COUNT(fb.FBID) > 6)

Answer 3

首先，UPDATE SET Status= 'C'语句无效后，SELECT语句的语法不正确，WHERE中的聚合函数不被允许，因此，经过这些更正后，可以使用子查询来实现所需的输出，如下所示：

UPDATE Bike SET Status= 'C'
FROM Bike b
INNER JOIN (
            SELECT b.BikeID 
            FROM Bike b
            INNER JOIN Fault ft ON b.BikeID=ft.BikeID
            INNER JOIN Feedback fb ON ft.FBID=fb.FBID
            WHERE (DATEPART(YEAR,fb.FbDateTIME)= 2018)
            AND (DATENAME(MONTH,fb.FbDateTIME)= 'January')
            GROUP BY BikeID HAVING (COUNT(fb.FBID)>6)) c ON c.bikeID = b.bikeID

更新无法使用内部联接

3 个答案: