动态SQL过程，数据透视表显示基于日期范围的计数

Question

我有一个包含多个用户条目的表。 我想根据传递给存储过程的日期范围来提取用户条目的数量。

开始日期：2017年11月9日 结束日期：11/11/2017

但是，根据日期范围内的天数，响应需要是动态的。

这是一种理想的格式：

Answer 1

如果您使用的是MySQL，那么这将是您想要的：

SELECT  UserID,
        UserName,
        SUM(Date = '2017-11-09') '2017-11-09',
        SUM(Date = '2017-11-10') '2017-11-10',
        SUM(Date = '2017-11-11') '2017-11-11'
FROM src
GROUP BY UserID

Answer 2

如果您使用的是SQL Server，可以尝试使用PIVOT：

SELECT *
FROM
(SELECT userID, userName, EntryDateTime
 FROM t) src
PIVOT
(COUNT(userID)
 FOR EntryDateTime IN (['2017-11-09'], ['2017-11-10'], ['2017-11-11'])) pvt

Answer 3

现在您已经提供了示例，我已经更新了我的答案，根据您提供的数据为您提供解决方案。

请注意，您可以更改日期范围，查询也会相应更新。

请记住，此SQL查询适用于SQL Server：

create table #tbl1 (
    [UserId] int
    ,[UserName] nvarchar(max)
    ,[EntryDateTime] datetime
);

insert into #tbl1 ([UserId],[UserName],[EntryDateTime])
values
    (1,'John Doe','20171109')
    ,(1,'John Doe','20171109')
    ,(1,'John Doe','20171110')
    ,(1,'John Doe','20171111')
    ,(2,'Mike Smith','20171109')
    ,(2,'Mike Smith','20171110')
    ,(2,'Mike Smith','20171110')
    ,(2,'Mike Smith','20171110')
;

-- declare variables
declare
    @p1 date
    ,@p2 date
    ,@diff int
    ,@counter1 int
    ,@counter2 int
    ,@dynamicSQL nvarchar(max)
;

-- set variables
set @p1 = '20171109';   -- ENTER THE START DATE IN THE FORMAT YYYYMMDD
set @p2 = '20171111';   -- ENTER THE END DATE IN THE FORMAT YYYYMMDD
set @diff = datediff(dd,@p1,@p2); -- used to calculate the difference in days
set @counter1 = 0;  -- first counter to be used in while loop
set @counter2 = 0;  -- second counter to be used in while loop
set @dynamicSQL = 'select pivotTable.[UserId] ,pivotTable.[UserName] as [Name] '; -- start of the dynamic SQL statement

-- to get the dates into the query in a dynamic way, you need to do a while loop (or use a cursor)
while (@counter1 < @diff)
begin
    set @dynamicSQL += ',pivotTable.[' + convert(nvarchar(10),dateadd(dd,@counter1,@p1),120) + '] '

    set @counter1 = (@counter1 +1)
end

-- continuation of the dynamic SQL statement
set @dynamicSQL += ' from (
    select
        t.[UserId]
        ,t.[UserName]
        ,cast(t.[EntryDateTime] as date) as [EntryDate]
        ,count(t.[UserId]) as [UserCount]
    from #tbl1 as t
    where
        t.[EntryDateTime] >= ''' + convert(nvarchar(10),@p1,120) + ''' ' +
        ' and t.[EntryDateTime] <= ''' + convert(nvarchar(10),@p2,120) + ''' ' +
    'group by
        t.[UserId]
        ,t.[UserName]
        ,t.[EntryDateTime]
    ) as mainQuery

    pivot (
        sum(mainQuery.[UserCount]) for mainQuery.[EntryDate]
            in ('
;

-- the second while loop which is used to create the columns in the pivot table
while (@counter2 < @diff)
begin
    set @dynamicSQL += ',[' + convert(nvarchar(10),dateadd(dd,@counter2,@p1),120) + ']'

    set @counter2 = (@counter2 +1)
end

-- continuation of the SQL statement
set @dynamicSQL += ')
    ) as pivotTable'
;

-- this is the easiet way I could think of to get rid of the leading comma in the query
set @dynamicSQL = replace(@dynamicSQL,'in (,','in (');

print @dynamicSQL   -- included this so that you can see the SQL statement that is generated

exec sp_executesql @dynamicSQL; -- this will run the generate dynamic SQL statement

drop table #tbl1;

请告诉我这是你要找的。