为以下问题识别和插入行的最有效方法是什么？
这是我的示例数据
vId StartDate EndDate Distance
------------------------------------
256 2015-03-04 2015-03-05 365
271 2015-03-04 2015-03-04 86
315 2015-03-05 2015-03-06 254
256 2015-03-07 2015-03-09 150
458 2015-03-10 2015-03-12 141
458 2015-03-15 2015-03-17 85
315 2015-03-15 2015-03-16 76
我想为vId之类的每个StartDate <> EndDate添加额外的行，而不仅仅是
315 2015-03-05 2015-03-06 254
256 2015-03-07 2015-03-09 150
我想展示以下内容
315 2015-03-05 2015-03-06 254
315 2015-03-06 2015-03-06 0
256 2015-03-07 2015-03-09 150
256 2015-03-08 2015-03-09 0
256 2015-03-09 2015-03-09 0
提前致谢。
答案 0 :(得分：1)
只是一个简单的插入：
Insert Into Table(vId, StartDate, EndDate, Distance)
Select vId, DateAdd(dd, 1, StartDate), EndDate, 0
From TableName
Where StartDate <> EndDate
如果您只想选择但不插入则：
Select vId, StartDate, EndDate, Distance
From TableName
Union All
Select vId, DateAdd(dd, 1, StartDate), EndDate, 0
From TableName
Where StartDate <> EndDate
修改
这假设最多有100天的差异。如果间隔较长，则可以添加更多交叉连接以增加可能的值：
declare @t table(vId int, StartDate date, EndDate date, Distance int)
insert into @t values
(315, '2015-03-05', '2015-03-06', 254),
(256, '2015-03-07', '2015-03-09', 150)
;with cte as(select row_number() over(order by (select 1)) as rn
from (values(1),(1),(1),(1),(1),(1),(1),(1),(1),(1)) t1(n)
cross join (values(1),(1),(1),(1),(1),(1),(1),(1),(1),(1)) t2(n)
)
select * from @t
union all
select t1.vId, ca.StartDate, t1.EndDate, 0
from @t t1
cross apply(select dateadd(dd, c.rn, StartDate) as StartDate
from cte c
where dateadd(dd, c.rn, t1.StartDate) <= t1.EndDate) as ca
where t1.StartDate <> t1.EndDate
order by vId, StartDate