Sql 这可以转换为基于集合的查询吗？

我有一个疑问：

if OBJECT_ID('tempdb..#tempA') is not null drop table #tempA

create table #tempA
(
    tempid varchar(5),
    tempdate smalldatetime
)

declare @loopdate smalldatetime
set @loopdate = '4/2/2013'

while (@loopdate <= '4/28/2013')
begin
    --Purpose is to get IDs not in TableB for each date period
    insert into #tempA (tempid, tempdate)
    select storeid, @loopdate
    from
    (
        select tableAid
        from tableA
        except
        select tableBid
        from tableB
        where tableBdate = @loopdate
    ) as idget

    set @loopdate = DATEADD(day, 1, @loopdate)
end

---

您可以在条件子句中包括日期范围，如下所示：

insert into #tempA (tempid, tempdate)
select tableAid
from tableA
except
select tableBid
from tableB
where tableBdate >= '4/2/2013' and tableBdate <= '4/28/2013';

---

仍然是一个循环，但可能更有效一点

while (@loopdate <= '4/28/2013')
begin
    --Purpose is to get IDs not in TableB for each date period
    insert into #tempA (tempid, tempdate)
    select storeid, @loopdate
    from
    (
        select tableAid
          from tableA
          left join tableB 
            on tableB.tableBid = tableA.tableAid
           and tableB.tableBdate = @loopdate 
         where tableB.tableBid is null
    ) as idget

    set @loopdate = DATEADD(day, 1, @loopdate)
end

这需要一些工作，但可能会让你一路设置

;WITH Days
as
(
    SELECT cast('4/2/2013' AS datetime ) as 'Day'
    UNION ALL
    SELECT DATEADD(DAY, +1, Day) as 'Day'
      FROM Days
     where [DAY] <= '4/28/2013'
)
SELECT tableA.tableAid, Days.[Day] 
  from Days 
  left join tableB 
    on tableB.tableBdate = Days.[Day]
  full join tableA 
    on tableB.tableBid = tableA.tableAid 
 where tableB.tableBid is null

---

这取决于tableA是否有日期，如果没有，则：

WITH DateList(DateDay) AS 
(  
     SELECT CAST('2013-04-28' AS DATETIME)
        UNION ALL
    SELECT DATEADD(DAY, DATEDIFF(DAY,0,DATEADD(DAY, -1, DateDay)),0)  
    FROM DateList  
    WHERE DateDay between '2013-04-03' and '2013-04-28'
)  
SELECT DISTINCT
    tableAid
    , DateDay 
FROM DateList
  cross join #tableA a
  left join #tableB b
    on tableAid = b.tableBid
    and b.tableBdate = DateDay
where
    b.tableBid is null
ORDER BY
    DateDay ASC

---

我很确定可以，但是你能发布源数据和期望的最终结果的示例吗？你不是在为tempdate插入一个值。这是行不通的。你怎么做可能是最好的办法。集合解决方案需要生成这组日期。左连接真的比除外连接更有效吗？只是想知道。@dotn00b除了使用索引外，还能使用什么？

insert into #tempA (tempid, tempdate)
select tableAid, tableAdate
from tableA
except
select tableBid,tableBdate
from tableB
where tableBdate >= '4/2/2013' and tableBdate <= '4/28/2013';

WITH DateList(DateDay) AS 
(  
     SELECT CAST('2013-04-28' AS DATETIME)
        UNION ALL
    SELECT DATEADD(DAY, DATEDIFF(DAY,0,DATEADD(DAY, -1, DateDay)),0)  
    FROM DateList  
    WHERE DateDay between '2013-04-03' and '2013-04-28'
)  
SELECT DISTINCT
    tableAid
    , DateDay 
FROM DateList
  cross join #tableA a
  left join #tableB b
    on tableAid = b.tableBid
    and b.tableBdate = DateDay
where
    b.tableBid is null
ORDER BY
    DateDay ASC