条件检查，single/multiple 值以逗号分隔的多列

Question

我有以下数据：

create table mtest
(
 id1 int,
 id2 int,
 id3 int,
 id4 int,
 name varchar(20)
);


insert into mtest values(1,11,2,33,'Test1');
insert into mtest values(2,12,4,3,'Test2');
insert into mtest values(4,13,6,44,'Test3');
insert into mtest values(7,15,17,4,'Test4');
insert into mtest values(10,65,9,5,'Test5');
insert into mtest values(7,65,4,5,'Test6');
insert into mtest values(37,11,4,15,'Test7');

我想查找值为 7 和 4 的 ID

预期输出:

id_column   value   names
-------------------------------------
id3         4       Test2,Test6,Test7
id1         7       Test4,Test6
id1         4       Test3
id4         4       Test4

尝试：

select distinct id_column,value,stuff((select ','+ name from mtest b where b.id1 = a.value or b.id2 = a.value or b.id3 = a.value or b.id4 =a.value for xml path('')), 1, 1,'') names
from
(
    select case when id1 in ('7','4') then 'id1'
                when id2 in ('7','4') then 'id2'
                when id3 in ('7','4') then 'id3'
                when id4 in ('7','4') then 'id4' else ''
            end as id_column,
            case when id1 in ('7','4') then id1
                when id2 in ('7','4') then id2
                when id3 in ('7','4') then id3
                when id4 in ('7','4') then id4 else ''
            end as value,
            name
    from mtest
) a
where a.id_column <> ''

但是得到错误的结果：

id_column   value   names
---------------------------------------------------
id1         4       Test2,Test3,Test4,Test6,Test7
id1         7       Test4,Test6
id3         4       Test2,Test3,Test4,Test6,Test7

而且我还担心 stuff 多个 or 条件的子句，因为 table 有超过 1000 万条记录。

Answer 1

首先，您需要规范化您的数据（我真的的意思是修复您的数据，而不是即时进行）。然后根据 ID 和 IDCol（在我的示例中）聚合字符串。

WITH CTE AS(
    SELECT V.ID,
           V.IDCol,
           M.[Name]
    FROM dbo.mtest M
         CROSS APPLY (VALUES(id1,'id1'),(id2,'id2'),(id3,'id3'),(id4,'id4'))V(ID,IDCol))
SELECT C.IDCol,
       C.ID,
       STUFF((SELECT ',' + x.[Name]
              FROM CTE x
              WHERE C.IDCol = x.IDCol
                AND C.ID = x.ID
              FOR XML PATH(''),TYPE).value('.','varchar(MAX)'),1,1,'') AS Names
FROM CTE C
WHERE C.ID IN (4,7)
GROUP BY C.IDCol,
         C.IDl

DB<>fiddle

旁注，SQL Server 2008 的（扩展）支持还剩 7 天。您确实需要尽快查看升级路径。

Answer 2

您可以执行 UNPIVOT AND XML Path，以下查询应该可以满足您的要求：

;WITH CTE AS (
    SELECT Col, Val, Name
    FROM mtest a
    UNPIVOT (Val FOR Col IN ([id1],[id2],[id3],[id4])) unpiv
    WHERE Val IN (4,7) )

SELECT Col, Val, 
Name = STUFF(
             (SELECT ',' + Name 
              FROM CTE t1
              WHERE t1.Col = t2.Col AND t1.Val = t2.Val 
              FOR XML PATH (''))
             , 1, 1, '')
FROM CTE t2
GROUP BY Col, Val

Answer 3

您可以通过 CTE 实现它：

;with cte as
(
  select * from (
    select case when id1 in ('7','4') then 'id1'
                when id2 in ('7','4') then 'id2'
                when id3 in ('7','4') then 'id3'
                when id4 in ('7','4') then 'id4'
            end as id_name,
            case when id1 in ('7','4') then id1
                when id2 in ('7','4') then id2
                when id3 in ('7','4') then id3
                when id4 in ('7','4') then id4
            end as id_column,
            name
    from @mtest
  ) a where id_column is not null
)

select id_column, id_name,
       (select name + ',' from cte where id_column = c.id_column and id_name = c.id_name for xml path(''))
from cte c
group by id_column, id_name

条件检查，single/multiple 值以逗号分隔的多列

Condition check, single/multiple value for multiple columns with comma separated column

sql

sql-server

sql-server-2008-r2