我有一个查询,用于跟踪每个交易时段处于风险中的交易者资金。如果在给定的一天没有交易,那么我需要从最后一个活动日结转至下一个活动日的日终值。这是我到目前为止所拥有的:
DECLARE @Start DATETIME = '2019-08-20'
DECLARE @End DATETIME = '2019-08-27'
DECLARE @history TABLE( Id INT, AccountId INT, AllocatedCapital MONEY, RunningAllocatedCapital MONEY,RN INT,SessionDate DATETIME)
INSERT INTO @history(Id, AccountId, AllocatedCapital, RunningAllocatedCapital,RN,SessionDate)
VALUES (362082, 1182, -170150.0000, -170150.0000, 1, '2019-08-20'),
(362090, 1182, -4167.9600, -199466.4600, 1, '2019-08-21'),
(362088, 1182, -10330.0000, -195298.5000, 2, '2019-08-21'),
(362086, 1182, -9454.5000, -184968.5000, 3, '2019-08-21'),
(362084, 1182, -5364.0000, -175514.0000, 4, '2019-08-21'),
(362094, 1182, -4140.0000, -207746.4600, 1, '2019-08-22'),
(362092, 1182, -4140.0000, -203606.4600, 2, '2019-08-22'),
(362105, 1182, 4140.0000, -187052.4800, 1, '2019-08-27')
;WITH tradingdays as (
SELECT TOP (DATEDIFF(DAY, @Start, @End) + 1)
DATEADD(DAY, ROW_NUMBER() OVER(ORDER BY a.object_id) - 1,@Start) SessionDate
FROM sys.all_objects a
CROSS JOIN sys.all_objects b
)
SELECT -MIN(RunningAllocatedCapital) MaxCapitalAtRisk,
-MAX(CASE H.RN WHEN 1 THEN H.RunningAllocatedCapital END)EodCapitalAtRisk,
C.SessionDate
FROM tradingdays C
LEFT JOIN @history H ON H.SessionDate = C.SessionDate
WHERE DATENAME(dw,C.SessionDate) NOT IN ('Saturday','Sunday')
GROUP BY C.SessionDate, H.SessionDate
ORDER BY C.SessionDate
代替此:
MaxCapitalAtRisk EodCapitalAtRisk SessionDate
170150.00 170150.00 2019-08-20 00:00:00.000
199466.46 199466.46 2019-08-21 00:00:00.000
207746.46 207746.46 2019-08-22 00:00:00.000
NULL NULL 2019-08-23 00:00:00.000
NULL NULL 2019-08-26 00:00:00.000
187052.48 187052.48 2019-08-27 00:00:00.000
我的结果集应如下所示:
MaxCapitalAtRisk EodCapitalAtRisk SessionDate
170150.00 170150.00 2019-08-20 00:00:00.000
199466.46 199466.46 2019-08-21 00:00:00.000
207746.46 207746.46 2019-08-22 00:00:00.000
207746.46 207746.46 2019-08-23 00:00:00.000
207746.46 207746.46 2019-08-26 00:00:00.000
187052.48 187052.48 2019-08-27 00:00:00.000
我知道在SQL Server中可以使用不使用子查询或游标的干净方法,但是我不记得该怎么做。
基本上,您正在使用lag()
选项寻找ignore nulls
。 SQL Server不支持此功能,但是我们可以使用“孤岛”技术来模拟它。
想法是使用条件总和或计数建立由一组“常规”记录(孤岛),然后是0到N个“缺失”记录(间隙)组成的记录组。然后,我们可以使用first_value()
来填充空白值:
with tradingdays as (
select @start SessionDate
union all select dateadd(day, 1, SessionDate) from tradingdays where SessionDate < @end
)
select
SessionDate,
first_value(MaxCapitalAtRisk) over(partition by grp order by SessionDate) MaxCapitalAtRisk,
first_value(EodCapitalAtRisk) over(partition by grp order by SessionDate) EodCapitalAtRisk
from (
select
td.SessionDate,
- min(RunningAllocatedCapital) MaxCapitalAtRisk,
- max(case h.rn when 1 then h.runningallocatedcapital end) EodCapitalAtRisk,
count(h.SessionDate) over(order by td.SessionDate) grp
from tradingdays td
left join @history h on h.SessionDate = td.SessionDate
where datename(dw, td.SessionDate) not in ('Saturday', 'Sunday')
group by td.SessionDate, h.SessionDate
) t
order by SessionDate
我更改了通用表表达式,该表生成了要使用递归的日期,因为我发现它更容易遵循-但这并没有改变逻辑,如果您更喜欢它,可以切换回原始cte。如果您坚持使用我的CTE,并且您的日期分布超过100天,则需要在查询的最后添加option(maxrecursion 0)
。
SessionDate | MaxCapitalAtRisk | EodCapitalAtRisk:---------------------- | :--------------- | :---------------2019-08-20 00:00:00.000 | 170150.0000 | 170150.00002019-08-21 00:00:00.000 | 199466.4600 | 199466.46002019-08-22 00:00:00.000 | 207746.4600 | 207746.46002019-08-23 00:00:00.000 | 207746.4600 | 207746.46002019-08-26 00:00:00.000 | 207746.4600 | 207746.46002019-08-27 00:00:00.000 | 187052.4800 | 187052.4800