select * from tb where charindex(',2,',','+ids+',')>0 or charindex(',11,',','+ids+',')>0

------解决方案--------------------
SQL code

select * from tb where charindex(',2,',','+ids+',')>0 or charindex(',11,',','+ids+',')>0

------解决方案--------------------

SQL code

create table A(ids varchar(100))
insert into A
select '2,21,23,27' union all
select '1,7,11,12' union all
select '5' union all
select '6,8'
go

declare @M varchar(50),
        @N xml
        
set @M='2,9,11'

set @N=convert(xml,'<r><c>'+replace(@M,',','</c><c>')+'</c></r>')
;with cte as
(
    select col=T.c.value('.[1]','varchar(20)')
    from @N.nodes('/r/c') T(c)
)

select a.col
from cte a left join A b on charindex(','+a.col+',',','+b.ids+',') > 0
where b.ids is null

drop table A

/************


col
--------------------
9

(1 行受影响)

------解决方案--------------------

SQL code

--> 测试数据：[A1]
if object_id('[A1]') is not null 
drop table [A1]
create table [A1]([ids] varchar(10))
insert [A1]
select '2,21,23,27' union all
select '1,7,11,12' union all
select '5' union all
select '6,8'
create table #tt(
ids varchar(2)
)
declare @str varchar(100)
set @str='1,9,11'
select @str='insert #tt 
             select '+REPLACE(@str,',',' union all select ')
exec(@str)
select * from #tt a
where exists(select 1 from [A1] b where CHARINDEX(','+a.ids+',',','+b.ids+',')>0)
/*

ids
1
11*/

------解决方案--------------------
建议不要用一个字段存放多个数据的方法，这种会导致查询的时候效率特别低下，往往查询的时间通常在100毫秒以上，甚至达到秒级的查询速度。
如果改成单个表来描述数据关系，查询时间通常在10毫秒以内。