我正在尝试从包含所有历史记录的事务表创建月度银行帐户对帐单。 我希望将期初余额作为第一行，然后使用递归cte在当时具有更新余额的当前月份交易。 我知道这可以通过表更新来完成，但递归是我正在寻找的。
表格结构如下：
declare @temp table (date datetime,tran_id int,cust_id int,tran_type char,amount int)
insert into @temp values('2017-06-06 22:05:10.703',1,1,'c',700),
('2017-06-12 22:05:10.703',2,1,'d',100),('2017-06-20 22:05:10.703',3,1,'c',200),
('2017-06-26 22:05:10.703',4,1,'d',450),(getdate()+1,5,1,'d',200),
(getdate()+2,6,1,'d',200),(getdate()+3,7,1,'c',500),
(getdate()+4,8,1,'d',300),(getdate()+5,9,1,'d',200),
('2017-06-18 22:05:10.703',12,1,'d',100)
所以在这里有第6个月和第7个月的交易。 当月的期初余额将是6月份所有交易的总和，这些交易将用作锚点以获得递归余额。 现在我希望select查询将date，tran_id，cust_id，credit，debit，balance作为结果集。
因此，如果表格包含以下数据：
date tran_id cust_id tran_type amount
2017-06-06 22:05:10.703 1 1 c 700
2017-06-12 22:05:10.703 2 1 d 100
2017-06-20 22:05:10.703 3 1 c 200
2017-06-26 22:05:10.703 4 1 d 450
2017-07-08 16:34:24.817 5 1 d 200
2017-07-09 16:34:24.817 6 1 d 200
2017-07-10 16:34:24.817 7 1 c 500
2017-07-11 16:34:24.817 8 1 d 300
2017-07-12 16:34:24.817 9 1 d 200
2017-06-18 22:05:10.703 12 1 d 100
The monthly statement for month 7 should be like:
opening balance of 250
date tran_id cust_id credit debit balance
2017-07-08 16:40:56.810 5 1 NULL 200 50
2017-07-09 16:40:56.810 6 1 NULL 200 -150
2017-07-10 16:40:56.810 7 1 500 NULL 350
2017-07-11 16:40:56.810 8 1 NULL 300 -50
2017-07-12 16:40:56.810 9 1 NULL 200 -250
我尝试过使用递归cte和sum窗口函数，但它不能逐行平衡连续平衡。
同样在cte中使用聚合函数也不是那么困难。
;with cte as
(
select cust_id,sum(case when tran_type='c' then amount*1 else amount*-1 end)
as 'opening balance' from @temp
where MONTH(date)=6 group by cust_id
),
cte2 as
(
select * from cte
union all
select t.cust_id,amount+[opening balance] as 'balance1' from @temp t join
cte2 c on c.cust_id=t.cust_id
where MONTH(date)=7
)
select * from cte2
或
;with cte as
(
select cust_id,sum(case when tran_type='c' then amount*1 else amount*-1 end)
as 'opening balance' from @temp
where MONTH(date)=6 group by cust_id
union all
select t.cust_id,SUM(amount+[opening balance]) as 'balance1' from @temp t
join cte c on c.cust_id=t.cust_id
where MONTH(date)=7
)
select * from cte
option (MAXRECURSION 1000)
我错过了什么？
答案 0 :(得分：1)
只需使用累计金额：
select t.*,
sum(case when tran_type = 'c' then amount else - amount end) over
(partition by cust_id order by date) as balance
from @temp t;
然后，您可以使用子查询或CTE选择范围：
select t.*
from (select t.*,
sum(case when tran_type = 'c' then amount else - amount end) over
(partition by cust_id order by date) as balance
from @temp t
) t
where . . .
您需要where的子查询，因此它不会影响累积总和。
编辑：
在SQL Server 2008中，您可以使用cross apply：
select t.*,
t2.balance
from @temp t cross apply
(select sum(case when t2.tran_type = 'c' then t2.amount else - t2.amount end) as balance
from @temp t2
where t2.cust_id = t.cust_id and t2.date <= t.date
) t2;
答案 1 :(得分：0)
对于旧版本，您可以使用CROSS APPLY来计算运行余额
;WITH opening_balance_cte
AS (SELECT cust_id,
Sum(CASE WHEN tran_type = 'c' THEN amount ELSE -amount END) AS opening_balance
FROM Yourtable
WHERE [date] < '2017-07-01'
GROUP BY cust_id)
SELECT *,
balance
FROM Yourtable a
JOIN opening_balance_cte ob
ON ob.cust_id = a.cust_id
CROSS apply (SELECT ob.opening_balance + Sum(CASE WHEN tran_type = 'c' THEN amount ELSE -amount END) AS balance
FROM Yourtable b
WHERE a.cust_id = b.cust_id
AND a.tran_id >= b.tran_id
AND b.[date] >= '2017-07-01'
AND b.[date] < '2017-08-01') cs
WHERE a.[date] >= '2017-07-01'
AND a.[date] < '2017-08-01'
如果你真的想知道如何使用Recursive CTE然后
;WITH opening_balance_cte
AS (SELECT cust_id,
Sum(CASE WHEN tran_type = 'c' THEN amount ELSE -amount END) AS opening_balance
FROM @temp
WHERE [date] < '2017-07-01'
GROUP BY cust_id),
rec_cte
AS (SELECT TOP 1 a.*,
opening_balance + CASE WHEN tran_type = 'c' THEN amount ELSE -amount END AS balance
FROM @temp a
JOIN opening_balance_cte o
ON a.cust_id = o.cust_id
WHERE a.[date] >= '2017-07-01'
AND a.[date] < '2017-08-01'
ORDER BY a.[date] ASC
UNION ALL
SELECT t.*,
rc.balance + CASE WHEN t.tran_type = 'c' THEN t.amount ELSE -t.amount END
FROM rec_cte rc
JOIN @temp t
ON t.cust_id = rc.cust_id
AND t.tran_id = rc.tran_id + 1)
SELECT *
FROM rec_cte