在has子句中不存在的列上进行分组

Question

我有一个简单的SQL查询，它带有GROUP BY，HAVING和ORDER BY子句。 HAVING子句在GROUP BY中有一些我不需要的字段，可以吗？ 因为我必须每小时对数据进行分组，并且HAVING中有一个日期字段，所以分组无法正常进行。 代码是：

alter procedure [dbo].[sp_metadata_inflow]
@grp_name varchar(40) , @subgrp_name varchar(40)
as
begin
declare @i as int , @j as int,@k as int,@d as datetime , @m as datetime,@y as datetime;
set @d = datepart(day,'2012-12-13 10:54:55.000');
set @m = datepart(month,'2012-12-13 10:54:55.000');
set @y = datepart(YEAR,'2012-12-13 10:54:55.000');
set @i = 1;
set @j = @i - 1;
while (@i <=24)
begin
(SELECT  top 5 @i,
         ContactReason,
         @grp_name,
         @subgrp_name,
         COUNT(*)
 FROM   [ISRM].[dbo].[ITSM01ISRM]
 GROUP  BY ContactReason,datepart(day,CreatedDate),CurrentGroup,CurrentSubGroup
 HAVING (
         datepart(day,CreatedDate)= @d AND datepart(MONTH,CreatedDate)= @m
         AND datepart(year,CreatedDate) = @y AND datepart(hour,CreatedDate) <= @i
         AND datepart(hour,CreatedDate) >=@j
        )
        AND (CurrentGroup = @grp_name) AND (CurrentSubGroup = @subgrp_name)
);
set @i = @i + 1;
set @j =  @i -1;
end
end
go

Answer 1

以下查询按小时将所有结果分组。 您为什么不想在GROUP BY中创建CreatedDate？

SELECT
    ContactReason,
    CurrentGroup,
    CurrentSubGroup,
    dateadd(hour, datediff(hour, 0, CreatedDate), 0),
    COUNT(1) 
FROM [ISRM].[dbo].[ITSM01ISRM] 
WHERE
    (CurrentGroup = @grp_name) AND (CurrentSubGroup = @subgrp_name)
GROUP BY 
    ContactReason,
    dateadd(hour, datediff(hour, 0, CreatedDate), 0),
    CurrentGroup,
    CurrentSubGroup;

Answer 2

要实际回答您的问题，似乎您只需要where子句中的这些条件。 它也看起来非常像SQL-Server语法，而不是标签所暗示的MySQL。

还值得注意的是，这是非常低效的：

    (datepart(day,CreatedDate)= @d 
AND datepart(MONTH,CreatedDate)= @m
AND datepart(year,CreatedDate) = @y 
AND datepart(hour,CreatedDate) <= @i 
AND datepart(hour,CreatedDate) >=@j ) 

在列上使用DATEPART不仅将强制函数对每一行进行求值，而且还消除了列上任何索引的好处。 写成Createddate >= '20130227 00:00' AND CreatedDate < '20130227 01:00'会更好。

此外，在每个循环中，您执行2小时的周期听起来都不像预期的行为。

最后，我无法想象返回24个结果集是处理数据的最佳方法，如果您希望每小时进行计数，那么将小时数作为列并执行一个查询并返回一个数据集就没有意义了吗？

例如

| ContactReason  | GroupName  | SubGroupName | 00:00 | 01:00 | 02:00 | 03:00 |.....| 23:00 |
|----------------+------------+--------------+-------+-------+-------+-------+.....+-------|
| Example Reason | Test Group | Sub Group    |   5   |   10  |    8  |    1  |.....|   14  |
| Another Reason | Test Group | Sub Group    |   3   |    1  |   13  |    8  |.....|   23  |

在这种情况下，您的查询可以写为

DECLARE @Date DATETIME = '20121213';

WITH Data AS
(       SELECT  ContactReason,
                GroupName = @grp_name,
                SubGroupName = @subgrp_name,
                CreatedHour = CAST(DATEADD(HOUR, DATEDIFF(HOUR, 0, Createddate), 0) AS TIME),
                [Value] = 1
        FROM    [ISRM].[dbo].[ITSM01ISRM] 
        WHERE   CurrentGroup = @grp_name
        AND     CurrentSubGroup = @subgrp_name
        AND     CreatedDate >= @Date
        AND     CreatedDate < DATEADD(DAY, 1, @Date)
)
SELECT  *
FROM    Data
        PIVOT
        (   COUNT(Value)
            FOR CreatedHour IN 
                (   [00:00], [01:00], [02:00], [03:00], [04:00], [05:00], 
                    [06:00], [07:00], [08:00], [09:00], [10:00], [11:00], 
                    [12:00], [13:00], [14:00], [15:00], [16:00], [17:00],
                    [18:00], [19:00], [20:00], [21:00], [22:00], [23:00]
        ) pvt;