我有一个查询输出这样的东西：
+-------+----+--------------+ | F_KEY | EV | OTHER_COLUMN | +-------+----+--------------+ | 100 | 1 | ... | | 100 | 2 | ... | | 150 | 2 | ... | | 100 | 3 | ... | | 150 | 4 | ... | +-------+----+--------------+
我确信我已经看到了一个聚合函数,它将它(使用GROUP BY F_KEY)变成这样的东西：
+-------+------------+--------------+ | F_KEY | ? | OTHER_COLUMN | +-------+------------+--------------+ | 100 | (1,2,3) | ... | | 150 | (2,4) | ... | +-------+------------+--------------+
意味着,它以某种方式将EV的价值“内爆”到一个单一的领域.我怎样才能做到这一点？不幸的是,我不记得该功能的名称.
我正在使用sql Server.
这是我查询的简化：
SELECT
F_KEY,EV,OTHER_COLUMN
FROM
TABLE1
JOIN
TABLE2 ON F_KEY = TABLE2.ID
WHERE
EVENT_TIME BETWEEN '2011-01-01 00:00:00.000' AND '2011-12-31 23:59:59.999'
ORDER BY
EVENT_TIME ASC
任何想法都表示赞赏！
解决方法
这是最好的连接方法,它不会像其他XML方法那样扩展特殊字符：
--Concatenation with FOR XML & eliminating control/encoded char expansion "& < >"
set nocount on;
declare @YourTable table (RowID int,HeaderValue int,ChildValue varchar(5))
insert into @YourTable VALUES (1,1,'CCC')
insert into @YourTable VALUES (2,'B<&>B')
insert into @YourTable VALUES (3,'AAA')
insert into @YourTable VALUES (4,3,'<br>')
insert into @YourTable VALUES (5,'A & Z')
set nocount off
SELECT
t1.HeaderValue,STUFF(
(SELECT
',' + t2.ChildValue
FROM @YourTable t2
WHERE t1.HeaderValue=t2.HeaderValue
ORDER BY t2.ChildValue
FOR XML PATH(''),TYPE
).value('.','varchar(max)'),''
) AS ChildValues
FROM @YourTable t1
GROUP BY t1.HeaderValue
OUTPUT：
HeaderValue ChildValues ----------- --------------- 1 CCC 2 AAA,B<&>B 3 <br>,A & Z (3 row(s) affected)
