SQL Server 2008 Express CONCAT() 不存在？
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SQL Server 2008 Express CONCAT() doesn't exist?
提问by screechOwl
I'm making switch from MySQL to SQL Server 2008 Express and can't seem to find a CONCAT()-esque function. I have two columns I'm trying to combine into a string and find unique combinations.
我正在从 MySQL 切换到 SQL Server 2008 Express，但似乎找不到 CONCAT() 式的函数。我有两列我试图组合成一个字符串并找到独特的组合。
id1 id2
001 abc1
002 qrs5
003 qrs5
003 abc1
... ...
When I try the following:
当我尝试以下操作时：
select id1, id2, concat(id1, ", ", id2) as combo1
FROM db1
group by combo1
I get the following error message:
我收到以下错误消息：
Msg 195, Level 15, State 10, Line 1
'concat' is not a recognized built-in function name.
消息 195，级别 15，状态 10，第 1 行
“concat”不是可识别的内置函数名称。
Any suggestions?
有什么建议？
回答by Bassam Mehanni
Maybe something like,
也许像，
SELECT DISTINCT id1, id2, id1 + ', ' + id2
would that work?
那行得通吗？
回答by william-1066
You can use CONCAT in SQL 2008 (if you REALLY want) by wrapping in brackets
你可以在 SQL 2008 中使用 CONCAT（如果你真的想要的话），用括号括起来
{fn CONCAT(id1,id2)} AS combo1
NOTE: CONCAT only takes two arguments, so you must nest them if you wish to concatenate more than two strings:
注意：CONCAT 只接受两个参数，所以如果你想连接两个以上的字符串，你必须嵌套它们：
{fn CONCAT(id1,{fn CONCAT(id2,id3)})} AS combo2
回答by David Acero
CONCATdoesn't exist in SQL Server 2008, it is new since SQL Server 2012.
CONCATSQL Server 2008 中不存在，它是自 SQL Server 2012 以来的新内容。
You could use instead:
你可以改用：
select id1, id2, id1 + ", " + id2 as combo1
FROM db1
group by combo1
