If object_id('tb') is not null 
    Drop table tb
Go
Create table tb(ID int,GradeRange varchar(20))
Go
Insert into tb
select 1,'0,999' union all
select 2,'1000,9999' union all
select 3,'10000,99999' union all
select 4,'100000,-1' 
Go

declare @i int
set @i=100009
Select *
from tb
where @i>=cast(left(graderange,charindex(',',graderange)-1) as int)
and @i<=case when stuff(graderange,1,charindex(',',graderange),'')='-1' then @i+1
 else cast(stuff(graderange,1,charindex(',',graderange),'') as int) end


/*
ID          GradeRange           
----------- -------------------- 
4           100000,-1

（所影响的行数为 1 行）
*/

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

declare @table table (ID int,GradeRange varchar(20))
insert into @table
select 1,'0,999' union all
select 2,'1000,9999' union all
select 3,'10000,99999' union all
select 4,'100000,-1'

declare @i int;set @i=2500 --25000  --25000

select ID from @table
where @i+1>=left(GradeRange,charindex(',',GradeRange)-1)+1 and
@i+1<=right(GradeRange,len(GradeRange)-charindex(',',GradeRange))+1
union all select top 1 4 from @table where @i>100001

------解决方案--------------------
建议表改成3个字段的，把后面两个上下限，分成2个字段，会容易控制很多。

------解决方案--------------------
探讨


建议表改成3个字段的，把后面两个上下限，分成2个字段，会容易控制很多。


------解决方案--------------------
declare @i

set @i=555
select id  
from T 
where @i between  cast(substring(GradeRange,1,(CHARINDEX(',', GradeRange)) as integer) and  cast(substring(GradeRange,CHARINDEX(',', GradeRange)+1 , len(GradeRange)) as integer)