if not object_id('tempdb..#Student') is null
begin
drop table #Student
end
create table #Student(stu_id nvarchar(36),stu_name nvarchar(36),stu_class nvarchar(36))
insert into #Student
select '1','a','b' union all
select '2','b','b' union all
select '3','c','b' union all
select '4','d','c' union all
select '5','e','d' 


select * from #Student where stu_id='c' or stu_name='c' or stu_class='c'

/*
3    c    b
4    d    c
*/

------解决方案--------------------
如果是模糊查询，就用各个字段 like '%输入的信息%'，然后or各个条件就可以了
如果是精确查询，就用各个字段 = '输入信息'，然后or各个条件
for example
SQL code

--模糊查询
select * from student   
 where stuID like '%' || your_text || '%'
    or stuName like '%' || your_text || '%'
    or [class] like '%' || your_text || '%'

--精确查询
select * from student   
 where stuID = your_text
    or stuName = your_text
    or [class] = your_text