用于计算每月记录的SQL查询

Question

我需要为特定用户每月访问次数构建一个数据集。我有一个包含这些字段的SQL表：

• 用户 nvarchar（30）
• DateVisit datetime

我现在想要实现的是按月为每个用户分组所有访问次数，如图所示：

我启动了查询，我可以通过此查询获取该月的月份和访问总数（不会被用户拆分）;

select  [1] AS January,
  [2] AS February,
  [3] AS March,
  [4] AS April,
  [5] AS May,
  [6] AS June,
  [7] AS July,
  [8] AS August,
  [9] AS September,
  [10] AS October,
  [11] AS November, 
  [12] AS December 
from
(
SELECT MONTH(DateVisit) AS month, [User] FROM UserVisit
) AS t
PIVOT (
COUNT([User])
  FOR month IN([1], [2], [3], [4], [5],[6],[7],[8],[9],[10],[11],[12])
) p

通过上面的查询，我得到了这个结果：

现在我想知道如何为用户添加一列，并按用户分割值。

Answer 1

你几乎就在那里：只需将用户添加到选择列表中：

select [Usr],
  [1] AS January,
  [2] AS February,
  [3] AS March,
  [4] AS April,
  [5] AS May,
  [6] AS June,
  [7] AS July,
  [8] AS August,
  [9] AS September,
  [10] AS October,
  [11] AS November, 
  [12] AS December 
from
(
SELECT MONTH(DateVisit) AS month, [User], [User] as [Usr] FROM UserVisit
) AS t
PIVOT (
COUNT([User])
  FOR month IN([1], [2], [3], [4], [5],[6],[7],[8],[9],[10],[11],[12])
) p

Answer 2

好的，两种解决方案都很好看。 Ali的答案有效，但我会使用SUM（）函数，我讨厌NULLS。让我们尝试两者，看看查询计划与执行时间。

我总是用数据创建一个测试表，这样我就不会给用户Aziale一个错误的答案。

下面的代码不是最漂亮的，但确实设置了一个测试用例。我在tempdb中创建了一个名为user_visits的数据库。对于每个月，我使用for循环来添加用户并为他们提供当月的创建开始日期。

现在我们有了数据，我们可以玩。

-- Drop the table
drop table tempdb.dbo.user_visits
go

-- Create the table
create table tempdb.dbo.user_visits
(
    uv_id int identity(1, 1),
    uv_visit_date smalldatetime,
    uv_user_name varchar(30)
);
go

-- January data
declare @cnt int = 1;
while @cnt <= 103
begin
    if (@cnt <= 21) 
        insert into tempdb.dbo.user_visits 
        (uv_visit_date, uv_user_name)
        values ('20130101', 'Patrick');

    if (@cnt <= 44) 
        insert into tempdb.dbo.user_visits 
        (uv_visit_date, uv_user_name)
        values ('20130101', 'Barbara');

    if (@cnt <= 65) 
        insert into tempdb.dbo.user_visits 
        (uv_visit_date, uv_user_name)
        values ('20130101', 'Danielle');

    if (@cnt <= 103) 
        insert into tempdb.dbo.user_visits 
        (uv_visit_date, uv_user_name)
        values ('20130101', 'John');

    set @cnt = @cnt + 1
end
go

-- February data
declare @cnt int = 1;
while @cnt <= 99
begin
    if (@cnt <= 29) 
        insert into tempdb.dbo.user_visits 
        (uv_visit_date, uv_user_name)
        values ('20130201', 'Patrick');

    if (@cnt <= 42) 
        insert into tempdb.dbo.user_visits 
        (uv_visit_date, uv_user_name)
        values ('20130201', 'Barbara');

    if (@cnt <= 55) 
        insert into tempdb.dbo.user_visits 
        (uv_visit_date, uv_user_name)
        values ('20130201', 'Danielle');

    if (@cnt <= 99) 
        insert into tempdb.dbo.user_visits 
        (uv_visit_date, uv_user_name)
        values ('20130201', 'John');

    set @cnt = @cnt + 1
end
go

-- March data
declare @cnt int = 1;
while @cnt <= 98
begin
    if (@cnt <= 25) 
        insert into tempdb.dbo.user_visits 
        (uv_visit_date, uv_user_name)
        values ('20130301', 'Patrick');

    if (@cnt <= 46) 
        insert into tempdb.dbo.user_visits 
        (uv_visit_date, uv_user_name)
        values ('20130301', 'Barbara');

    if (@cnt <= 75) 
        insert into tempdb.dbo.user_visits 
        (uv_visit_date, uv_user_name)
        values ('20130301', 'Danielle');

    if (@cnt <= 98) 
        insert into tempdb.dbo.user_visits 
        (uv_visit_date, uv_user_name)
        values ('20130301', 'John');

    set @cnt = @cnt + 1
end
go

-- April data
declare @cnt int = 1;
while @cnt <= 91
begin
    if (@cnt <= 32) 
        insert into tempdb.dbo.user_visits 
        (uv_visit_date, uv_user_name)
        values ('20130401', 'Patrick');

    if (@cnt <= 48) 
        insert into tempdb.dbo.user_visits 
        (uv_visit_date, uv_user_name)
        values ('20130401', 'Barbara');

    if (@cnt <= 60) 
        insert into tempdb.dbo.user_visits 
        (uv_visit_date, uv_user_name)
        values ('20130401', 'Danielle');

    if (@cnt <= 91) 
        insert into tempdb.dbo.user_visits 
        (uv_visit_date, uv_user_name)
        values ('20130401', 'John');

    set @cnt = @cnt + 1
end
go

-- May data
declare @cnt int = 1;
while @cnt <= 120
begin
    if (@cnt <= 40) 
        insert into tempdb.dbo.user_visits 
        (uv_visit_date, uv_user_name)
        values ('20130501', 'Patrick');

    if (@cnt <= 41) 
        insert into tempdb.dbo.user_visits 
        (uv_visit_date, uv_user_name)
        values ('20130501', 'Barbara');

    if (@cnt <= 70) 
        insert into tempdb.dbo.user_visits 
        (uv_visit_date, uv_user_name)
        values ('20130501', 'Danielle');

    if (@cnt <= 120) 
        insert into tempdb.dbo.user_visits 
        (uv_visit_date, uv_user_name)
        values ('20130501', 'John');

    set @cnt = @cnt + 1
end
go

-- June data
declare @cnt int = 1;
while @cnt <= 103
begin
    if (@cnt <= 17) 
        insert into tempdb.dbo.user_visits 
        (uv_visit_date, uv_user_name)
        values ('20130601', 'Patrick');

    if (@cnt <= 45) 
        insert into tempdb.dbo.user_visits 
        (uv_visit_date, uv_user_name)
        values ('20130601', 'Barbara');

    if (@cnt <= 62) 
        insert into tempdb.dbo.user_visits 
        (uv_visit_date, uv_user_name)
        values ('20130601', 'Danielle');

    if (@cnt <= 103) 
        insert into tempdb.dbo.user_visits 
        (uv_visit_date, uv_user_name)
        values ('20130601', 'John');

    set @cnt = @cnt + 1
end
go

-- July data
declare @cnt int = 1;
while @cnt <= 99
begin
    if (@cnt <= 20) 
        insert into tempdb.dbo.user_visits 
        (uv_visit_date, uv_user_name)
        values ('20130701', 'Patrick');

    if (@cnt <= 43) 
        insert into tempdb.dbo.user_visits 
        (uv_visit_date, uv_user_name)
        values ('20130701', 'Barbara');

    if (@cnt <= 66) 
        insert into tempdb.dbo.user_visits 
        (uv_visit_date, uv_user_name)
        values ('20130701', 'Danielle');

    if (@cnt <= 99) 
        insert into tempdb.dbo.user_visits 
        (uv_visit_date, uv_user_name)
        values ('20130701', 'John');

    set @cnt = @cnt + 1
end
go

-- August data
declare @cnt int = 1;
while @cnt <= 98
begin
    if (@cnt <= 26) 
        insert into tempdb.dbo.user_visits 
        (uv_visit_date, uv_user_name)
        values ('20130801', 'Patrick');

    if (@cnt <= 47) 
        insert into tempdb.dbo.user_visits 
        (uv_visit_date, uv_user_name)
        values ('20130801', 'Barbara');

    if (@cnt <= 71) 
        insert into tempdb.dbo.user_visits 
        (uv_visit_date, uv_user_name)
        values ('20130801', 'Danielle');

    if (@cnt <= 98) 
        insert into tempdb.dbo.user_visits 
        (uv_visit_date, uv_user_name)
        values ('20130801', 'John');

    set @cnt = @cnt + 1
end
go

-- September data
declare @cnt int = 1;
while @cnt <= 91
begin
    if (@cnt <= 25) 
        insert into tempdb.dbo.user_visits 
        (uv_visit_date, uv_user_name)
        values ('20130901', 'Patrick');

    if (@cnt <= 49) 
        insert into tempdb.dbo.user_visits 
        (uv_visit_date, uv_user_name)
        values ('20130901', 'Barbara');

    if (@cnt <= 59) 
        insert into tempdb.dbo.user_visits 
        (uv_visit_date, uv_user_name)
        values ('20130901', 'Danielle');

    if (@cnt <= 91) 
        insert into tempdb.dbo.user_visits 
        (uv_visit_date, uv_user_name)
        values ('20130901', 'John');

    set @cnt = @cnt + 1
end
go

-- October data
declare @cnt int = 1;
while @cnt <= 120
begin
    if (@cnt <= 25) 
        insert into tempdb.dbo.user_visits 
        (uv_visit_date, uv_user_name)
        values ('20131001', 'Patrick');

    if (@cnt <= 40) 
        insert into tempdb.dbo.user_visits 
        (uv_visit_date, uv_user_name)
        values ('20131001', 'Barbara');

    if (@cnt <= 73) 
        insert into tempdb.dbo.user_visits 
        (uv_visit_date, uv_user_name)
        values ('20131001', 'Danielle');

    if (@cnt <= 120) 
        insert into tempdb.dbo.user_visits 
        (uv_visit_date, uv_user_name)
        values ('20131001', 'John');

    set @cnt = @cnt + 1
end
go

-- November data
declare @cnt int = 1;
while @cnt <= 101
begin
    if (@cnt <= 32) 
        insert into tempdb.dbo.user_visits 
        (uv_visit_date, uv_user_name)
        values ('20131101', 'Patrick');

    if (@cnt <= 50) 
        insert into tempdb.dbo.user_visits 
        (uv_visit_date, uv_user_name)
        values ('20131101', 'Barbara');

    if (@cnt <= 65) 
        insert into tempdb.dbo.user_visits 
        (uv_visit_date, uv_user_name)
        values ('20131101', 'Danielle');

    if (@cnt <= 101) 
        insert into tempdb.dbo.user_visits 
        (uv_visit_date, uv_user_name)
        values ('20131101', 'John');

    set @cnt = @cnt + 1
end
go

-- December data
declare @cnt int = 1;
while @cnt <= 90
begin
    if (@cnt <= 40) 
        insert into tempdb.dbo.user_visits 
        (uv_visit_date, uv_user_name)
        values ('20131201', 'Patrick');

    if (@cnt <= 52) 
        insert into tempdb.dbo.user_visits 
        (uv_visit_date, uv_user_name)
        values ('20131201', 'Barbara');

    if (@cnt <= 61) 
        insert into tempdb.dbo.user_visits 
        (uv_visit_date, uv_user_name)
        values ('20131201', 'Danielle');

    if (@cnt <= 90) 
        insert into tempdb.dbo.user_visits 
        (uv_visit_date, uv_user_name)
        values ('20131201', 'John');

    set @cnt = @cnt + 1
end
go

请不要在编码中使用保留字作为列名 - IE - 月是保留字。

下面的代码为您提供了正确的答案。

-- Grab the data (1)
select 
  my_user, 
  [1] AS January,
  [2] AS Febrary,
  [3] AS March,
  [4] AS April,
  [5] AS May,
  [6] AS June,
  [7] AS July,
  [8] AS August,
  [9] AS September,
  [10] AS October,
  [11] AS November, 
  [12] AS December 
from
(
  SELECT MONTH(uv_visit_date) AS my_month, uv_user_name as my_user FROM tempdb.dbo.user_visits
) AS t
PIVOT (
  COUNT(my_month)
  FOR my_month IN([1], [2], [3], [4], [5],[6],[7],[8],[9],[10],[11],[12])
) as p

-- Grab the data (2)
SELECT  uv_user_name
       , SUM(CASE WHEN  MONTH(uv_visit_date) = 1 THEN 1 ELSE 0 END) January
       , SUM(CASE WHEN  MONTH(uv_visit_date) = 2 THEN 1 ELSE 0 END) Feburary
       , SUM(CASE WHEN  MONTH(uv_visit_date) = 3 THEN 1 ELSE 0 END) March
       , SUM(CASE WHEN  MONTH(uv_visit_date) = 4 THEN 1 ELSE 0 END) April
       , SUM(CASE WHEN  MONTH(uv_visit_date) = 5 THEN 1 ELSE 0 END) May
       , SUM(CASE WHEN  MONTH(uv_visit_date) = 6 THEN 1 ELSE 0 END) June
       , SUM(CASE WHEN  MONTH(uv_visit_date) = 7 THEN 1 ELSE 0 END) July
       , SUM(CASE WHEN  MONTH(uv_visit_date) = 8 THEN 1 ELSE 0 END) August
       , SUM(CASE WHEN  MONTH(uv_visit_date) = 9 THEN 1 ELSE 0 END) September
       , SUM(CASE WHEN  MONTH(uv_visit_date) = 10 THEN 1 ELSE 0 END) October
       , SUM(CASE WHEN  MONTH(uv_visit_date) = 11 THEN 1 ELSE 0 END) November
       , SUM(CASE WHEN  MONTH(uv_visit_date) = 12 THEN 1 ELSE 0 END) December
FROM tempdb.dbo.user_visits
GROUP BY uv_user_name

进行此类分析时，请始终清除缓存/缓冲区并获取I / O.

-- Show time & i/o
SET STATISTICS TIME ON
SET STATISTICS IO ON
GO

-- Remove clean buffers & clear plan cache
CHECKPOINT 
DBCC DROPCLEANBUFFERS 
DBCC FREEPROCCACHE
GO


-- Solution 1
SQL Server parse and compile time: 
   CPU time = 0 ms, elapsed time = 42 ms.

(4 row(s) affected)
Table 'Worktable'. Scan count 0, logical reads 0, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.
Table 'user_visits'. Scan count 1, logical reads 11, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.

 SQL Server Execution Times:
   CPU time = 16 ms,  elapsed time = 5 ms.

-- Solution 2
SQL Server parse and compile time: 
   CPU time = 0 ms, elapsed time = 0 ms.

(4 row(s) affected)
Table 'Worktable'. Scan count 0, logical reads 0, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.
Table 'user_visits'. Scan count 1, logical reads 11, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.

 SQL Server Execution Times:
   CPU time = 16 ms,  elapsed time = 5 ms.

两种解决方案都具有相同数量的读取，工作表等。但是，SUM（）解决方案只需少一个运算符。

我要给那两个回答赞美的人+1 !!

Answer 3

SELECT  [User]
       , COUNT(CASE WHEN  MONTH(DateVisit) = 1 THEN 1 ELSE NULL END) January
       , COUNT(CASE WHEN  MONTH(DateVisit) = 2 THEN 1 ELSE NULL END) Feburary
       , COUNT(CASE WHEN  MONTH(DateVisit) = 3 THEN 1 ELSE NULL END) March
       , COUNT(CASE WHEN  MONTH(DateVisit) = 4 THEN 1 ELSE NULL END) April
       , COUNT(CASE WHEN  MONTH(DateVisit) = 5 THEN 1 ELSE NULL END) May
       , COUNT(CASE WHEN  MONTH(DateVisit) = 6 THEN 1 ELSE NULL END) June
       , COUNT(CASE WHEN  MONTH(DateVisit) = 7 THEN 1 ELSE NULL END) July
       , COUNT(CASE WHEN  MONTH(DateVisit) = 8 THEN 1 ELSE NULL END) August
       , COUNT(CASE WHEN  MONTH(DateVisit) = 9 THEN 1 ELSE NULL END) September
       , COUNT(CASE WHEN  MONTH(DateVisit) = 10 THEN 1 ELSE NULL END) October
       , COUNT(CASE WHEN  MONTH(DateVisit) = 11 THEN 1 ELSE NULL END) November
       , COUNT(CASE WHEN  MONTH(DateVisit) = 12 THEN 1 ELSE NULL END) December
FROM Table_Name
GROUP BY [USER]