请教SQL问题，拜托高手来帮帮我~~~

Question

数据库里存在的形式是1,2,3这样  我想把2替换成12   其他不动   我该如何做一下   高手帮帮忙  拜托~~~

Answer 1

--????
replace('1,2,3',',2,',',12,')

Answer 2

declare @s varchar(10),@old varchar(10),@new varchar(10)
set @s='1,2,3'
set @old='2'
set @new='12'
select replace(@s,','+@old+',',','+@new+',')/*
                                                                                                                                                                                                                                                                 
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- 
1,12,3（所影响的行数为 1 行）*/

Answer 3

update tb set col = replace(col,',2,',',12,')

Answer 4

1> select replace('1,2,3',',2,',',12,')
2> go----------------------------------------
1,12,3(1 rows affected)
1>

Answer 5

replace('1,2,3',',2,',',12,')
 在我这运行为什么会报错呢？