子查询中的SQL Group By语句

我试图编写一个查询，返回每个员工每月进行的“主动呼叫案例”的数量以及所有案例的总数。基本上，我希望返回3列；一个EmployeeName，该月的主动呼叫数，以及该月的总呼叫数。为了尝试实现这一点，我使用了一个子查询。以下是我到目前为止的情况：

Select OpenedByName AS EmployeeName, Count(OpenedByName) As NumberOfProactiveCallsMONTH,
  (Select Count(OpenedByName)
   From table1
   Where OpenDate Between '2/1/2014' and '3/1/2014' Group By OpenedByName) AS
   TotalTicketsMONTH
From table1
Where OpenDate Between '2/1/2014' and '3/1/2014' AND ProblemType = 17 
Group By OpenedByName

运行查询后，我得到的错误是：

"Msg 512, Level 16, State 1, Procedure SalesMTDSubQuery, Line 7 Subquery returned
more than 1 value. This is not permitted when the subquery follows =, !=, <, <= ,
>, >= or when the subquery is used as an expression."

“Msg 512，级别16，状态1，过程SalesMTDSubQuery，返回第7行子查询
超过1个值。当子查询后跟=、！=、=或子查询用作表达式时，不允许使用此值。“

我认为它返回这个错误是因为我在子查询中添加了GroupBy语句。当我删除GroupBy时，它只会为每个员工返回相同的值。我对使用SQL还相当陌生，所以我不确定有什么好方法可以解决这个问题。任何帮助都将不胜感激

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谢谢

您需要将子选择与外部语句关联起来，否则，正如您所注意到的，您会在子选择中返回多行不起作用的语句

SELECT  OpenedByName AS EmployeeName
      , COUNT(OpenedByName) AS NumberOfProactiveCallsMONTH
      , ( SELECT    COUNT(OpenedByName)
          FROM      table1 b
          WHERE     OpenDate BETWEEN '2/1/2014' AND '3/1/2014'
                AND b.OpenedByName = a.OpenedByName
          GROUP BY  OpenedByName
        ) AS TotalTicketsMONTH
FROM    table1 a
WHERE   OpenDate BETWEEN '2/1/2014' AND '3/1/2014'
        AND ProblemType = 17
GROUP BY OpenedByName

但通过使用条件和而不是子选择，您可以大大简化这一过程：

SELECT  OpenedByName AS EmployeeName
      , SUM(ProblemType = 17) NumberOfProactiveCallsMONTH
      , COUNT(OpenedByName) AS TotalTicketsMONTH
FROM    table1
WHERE   OpenDate BETWEEN '2/1/2014' AND '3/1/2014'
GROUP BY OpenedByName

---

像这样的怎么样

SELECT  OpenedByName AS EmployeeName,
        SUM(CASE WHEN ProblemType = 17 THEN 1 ELSE 0 END) AS NumberOfProactiveCallsMONTH,
        COUNT(1) TotalTicketsMONTH
FROM Table1
Where OpenDate Between '2/1/2014' and '3/1/2014' 
GROUP BY OpenedByName

Select OpenedByName AS EmployeeName, Count(OpenedByName) As NumberOfProactiveCallsMONTH,
  (Select Count(OpenedByName)
   From table1 t
   Where OpenDate Between '2/1/2014' and '3/1/2014' 
   AND t.OpenedByName = t1.OpenedByName) AS
   TotalTicketsMONTH
From table1 t1
Where OpenDate Between '2/1/2014' and '3/1/2014' AND ProblemType = 17 
Group By OpenedByName

收到的错误是由于将子查询用作列时，它不能返回超过1个值

现在按照您构建它的方式，它将返回每个OpenedByName的所有

COUNT

值，而不是每个OpenedBy返回一个值

如果您确实希望使用query，则需要将select列中的查找限制为实际的OpenedByName。大概是

SELECT  OpenedByName AS EmployeeName,
        SUM(CASE WHEN ProblemType = 17 THEN 1 ELSE 0 END) AS NumberOfProactiveCallsMONTH,
        COUNT(1) TotalTicketsMONTH
FROM Table1
Where OpenDate Between '2/1/2014' and '3/1/2014' 
GROUP BY OpenedByName

Select OpenedByName AS EmployeeName, Count(OpenedByName) As NumberOfProactiveCallsMONTH,
  (Select Count(OpenedByName)
   From table1 t
   Where OpenDate Between '2/1/2014' and '3/1/2014' 
   AND t.OpenedByName = t1.OpenedByName) AS
   TotalTicketsMONTH
From table1 t1
Where OpenDate Between '2/1/2014' and '3/1/2014' AND ProblemType = 17 
Group By OpenedByName

你可以这样用

Select a.OpenedByName AS EmployeeName, Count(a.OpenedByName) As NumberOfProactiveCallsMONTH,
b.TotalTicketsMONTH  AS   TotalTicketsMONTH
From table1 a
INNER JOIN   
  (Select OpenedByName ,Count(OpenedByName) AS TotalTicketsMONTH   From table1
  Where OpenDate Between '2/1/2014' and '3/1/2014' Group By OpenedByName) b ON
  a.OpenedByName =  b.OpenedByName
Where a.OpenDate Between '2/1/2014' and '3/1/2014' AND a.ProblemType = 17 
Group By a.OpenedByName

---

您需要将一个关系从内部查询放到外部查询：

SELECT  t1.OpenedByName AS EmployeeName, 
        COUNT(t1.OpenedByName) As NumberOfProactiveCallsMONTH,
        (   SELECT  COUNT(OpenedByName)
            FROM    table1 t2
            WHERE   t2.OpenDate BETWEEN '2/1/2014' AND '3/1/2014'
            AND     t1.OpenedByName = t2.OpenedByName
        ) AS TotalTicketsMONTH
FROM    table1 t1
WHERE   t1.OpenDate BETWEEN '2/1/2014' AND '3/1/2014' 
AND     t1.ProblemType = 17 
GROUP BY t1.OpenedByName;

但是，您可以通过使用条件聚合来简化查询（即，仅当满足其他条件时才计算）：

下一个改进是将您的日期格式更改为非特定文化的日期格式-是

2/1/2014

1月2日还是2月1日？如果使用

yyyyMMdd

，则没有歧义

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最后，您的查询将包括3月1日午夜打开的票据，我怀疑这些票据不应包含在2月份的数据中，您最好使用

=

和`子查询的目的是什么？如果您按OpenedName分组，然后获得一个计数，这还不够吗？这是我使用的解决方案，效果非常好。我只是想知道问题的一部分。获得每月总票数的计数（1）是多少？谢谢