SQL Server中以逗号分隔的列

Question

我有一个问题：我有两张桌子

Table1有两列

Col1   Col2 
----  ------
a     value1
b     value1
b     value1

Table2

Col1   Col2 
----  ------
1     a,b
2     a,c
3     a,b,c

我想要结果

Col1   Col2
-----  -----
a      1,2,3
b      1,3
c      2,3

Answer 1

WITH C AS
(
  SELECT T2.Col1,
         S.Item
  FROM Table2 AS T2
    CROSS APPLY dbo.SplitStrings(T2.Col2, ',') AS S
)
SELECT C1.Item AS Col1,
       (
       SELECT ','+CAST(C2.Col1 AS VARCHAR(10))
       FROM C AS C2
       WHERE C1.Item = C2.Item
       ORDER BY C2.Col1
       FOR XML PATH(''), TYPE
       ).value('substring(text()[1], 2)', 'VARCHAR(MAX)') AS Col2
FROM C AS C1
GROUP BY C1.Item

SQL Fiddle

Answer 2

试试这个：

注意：未经过测试

select col1, [col2],
(select col1+',' from Table2 where Col2=ID
group by col1 for xml path('')) AS Col2
From Table1