计算sql行，将每行的值添加到下一行

Question

我有两列，我想将每一行的值添加到下一行。 我的两列四行的表是这样的：

date           users
2011-01-01      1
2011-02-02      1
2011-03-02      2
2011-04-02      4

我希望用户显示如下，并将每行添加到它的上一行值中：

用户：

1
2
4
8

MS SQL Server是否有执行此操作的功能？

谢谢

Answer 1

在SQL Server 2005及更高版本（未指定版本）中，您可以使用两个CTE（公用表表达式）执行类似的操作-第一个称为UserSequence可以将数据按顺序排列并按顺序进行数字（ Sequence ）和第二个递归CTE（公用表表达式）来计算运行总计：

;WITH UserSequence AS
(
    SELECT 
        Date, Users, ROW_NUMBER() OVER(ORDER BY Date) as 'Sequence'
    FROM 
        dbo.YourTable
),
UserValues AS
(
  SELECT  
     u.Users AS 'UserValue', u.Date, u.Sequence
  FROM UserSequence u
  WHERE Sequence = 1

  UNION ALL 

  SELECT  
     u.Users + uv.UserValue AS 'UserValue', u.Date, u.Sequence
  FROM UserSequence u
  INNER JOIN UserValues uv ON u.Sequence = uv.Sequence + 1
)
SELECT
    Date, Sequence, UserValue AS 'Users'
FROM 
    UserValues
ORDER BY 
    Sequence

那应该给你这样的输出：

Date                      Sequence    Users
2011-01-01 00:00:00.000       1         1
2011-02-02 00:00:00.000       2         2
2011-03-02 00:00:00.000       3         4
2011-04-02 00:00:00.000       4         8

Answer 2

With cte_Test(Sequence,Name,Value)
As
(
select  ROW_NUMBER() OVER(ORDER BY value) as 'Sequence' ,name,value from test
)

select t1.Name,sum(T2.Value) AS Value from cte_Test t1 
cross JOIN cte_Test t2 where t2.Sequence <= t1.Sequence 
group BY t1.Name
order by 2

Answer 3

您可以按照以下方法进行操作：

set @total_users = 0;
select users, @total_users:=@total_users + users as total_users from tablename;

Answer 4

通过交叉连接可以做到这一点。 如果您的表列按升序排列。

select <T1.Text>,sum(T2.Value) AS 'Commulative Value' from <Your Table name>t1 
cross JOIN <Your Table name> t2 where t2.value<= t1.value
group BY t1.text
order by value

Answer 5

这是ANSI SQL中的解决方案：

SELECT users + lag(users) over (order by users)
FROM your_table
ORDER BY users

适用于PostgreSQL，Oracle，DB2和Teradata（SQL Server确实具有窗口功能，但不幸的是没有lag（）函数）