Question

我有一个返回工作日的查询

Select PERSON_NAME, PERSON_DAY from PERSON_DAYS WHERE PERSON_ID = @myId

说我获得了

John 1 (mo)
John 3 (mo tu)
John 8 (th)

我需要在忙碌的所有日子里为约翰取得。如何在此查询中的PERSON_DAY列上使用逻辑OR？

结果应该是11（mo tu th）

Answer 1

这是我迄今为止最好的

;with PowersOf2
as
(
    select 1 as Number
    union all
    select A.Number * 2 from PowersOf2 as A where A.Number < 64
)
select P.PERSON_NAME, sum(distinct P.PERSON_DAY & PowersOf2.Number)
from PERSON_DAYS as P
    left outer join PowersOf2 on PowersOf2.Number <= P.PERSON_DAY
where P.PERSON_ID = @myId
group by P.PERSON_NAME

SQL FIDDLE EXAMPLE

Answer 2

如果我理解正确，您可以结合使用bitwise operator and和汇总功能sum来完成您想要的工作。

示例：

with person_days as (
      select 'John' as person_name, 1 as weekday --mo
union select 'John',  3  -- mo, tu
union select 'John',  8  -- th
union select 'Jane',  1  -- mo
union select 'Jane',  9  -- mo, th
union select 'Jane', 40  -- th, sa
),
Bits AS ( 
          SELECT   1 AS BitMask --mo
UNION ALL SELECT   2            --tu
UNION ALL SELECT   4            --we
UNION ALL SELECT   8            --th
UNION ALL SELECT  16            --fr
UNION ALL SELECT  32            --sa
UNION ALL SELECT  64            --su
UNION ALL SELECT 128
)
, person_single_days as (
select distinct person_name, weekday & bits.BitMask single_weekday
  from person_days 
       inner join bits on person_days.weekday & bits.BitMask > 0
)
select person_name, sum(single_weekday) weekdays
  from person_single_days
 group by person_name;

结果：

person_name weekdays
----------- -----------
Jane        41
John        11

Answer 3

罗马的CTE“启发”:(注意第一个CTE只生成演示数据）

with p as 
(
    select 'John' as PERSON_NAME, 1 as PERSON_DAY
    union
    select 'John', 3 
    union
    select 'John', 8
    union
    select 'Jane', 2
    union
    select 'Jane', 4
),
cte as
(
    select PERSON_NAME, PERSON_DAY from p
    union all
    select cte2.PERSON_NAME, p.PERSON_DAY | cte2.PERSON_DAY 
        from p 
        inner join cte as cte2 on p.PERSON_NAME = cte2.PERSON_NAME 
        where p.PERSON_DAY & cte2.PERSON_DAY = 0
)   
select PERSON_NAME, MAX(PERSON_DAY) from cte
group by PERSON_NAME

Answer 4

我认为您正在寻找的是一个执行OR的自定义聚合。您可以在.NET中使用SQL CLR编写它。这可能是最干净的解决方案。它也可以重复使用。

或者，您可以使用基于游标的循环来计算结果。

您也可以（误）使用CTE来实现此目的。

SQL列上的二进制“OR”操作

4 个答案: