Sql 使用和函数

我有以下结构的表：

TestTable ID INT，LoanID INT，Amount INT

ID  LoanID  Amount
1   1        20
2   1        30
3   1        15
4   2        40
5   2        20
6   3        50

我想用这个场景计算贷款金额

ID  LoanID  Amount  Sum
1   1       20      20
2   1       30      50
3   1       15      65
4   2       40      40
5   2       20      60
6   3       50      50

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获取此总和的最佳方法是什么？当然，没有光标：

不幸的是，SQL Server 2008没有执行累积总和的干净函数，因此您需要使用相同的LoadID将前面的所有行相加：

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您可以使用相关子查询来获取：

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通过使用窗口功能：

select *, sum(amount) over (partition by loanid order by id) as "sum" from testtable;

SQL server 2012：

SQL server 2008：

它可以在SQL server 2012上运行，但不能在使用SQLFIDLE的SQL server 2008上运行。

试试这个

  SELECT b.id,a.LoanID,b.Amount,
           Sum(a.Amount) AS [Sum]
    FROM   #temp_table a
    JOIN   #temp_table b ON a.id <= b.id
                  AND a.LoanID = b.LoanID
    GROUP  BY b.id,a.LoanID,b.Amount

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这不是累计和，看看OP输出，Id 4的和为40，Id 3的和为4065@RADAR这是每个贷款组的累计值。@D Stanley，您的查询结果是良好的+1

SELECT t.ID, t.LoanID, t.Amount,
       [Sum] = (SELECT SUM(AMOUNT)
                FROM TestTable t2
                WHERE t.LoanID=t2.LoanID
                AND t2.ID <= t.ID)
FROM TestTable t

select ID, LoanID, Amount, 
       (select sum(Amount)
        from TestTable A
        where  A.LoanID = B.LoanID and
               A.ID <= B.ID
       ) as Sum
from TestTable B;

select *, sum(amount) over (partition by loanid order by id) as "sum" from testtable;

  SELECT b.id,a.LoanID,b.Amount,
           Sum(a.Amount) AS [Sum]
    FROM   #temp_table a
    JOIN   #temp_table b ON a.id <= b.id
                  AND a.LoanID = b.LoanID
    GROUP  BY b.id,a.LoanID,b.Amount