create table tb(val varchar(10),vc varchar(10))
insert into tb
select 'A','a' union all
select 'b','B' union all
select 'a','A'
go

select *
from tb
where val = 'a' or vc = 'b' collate Chinese_PRC_CS_AI

/*
val        vc
---------- ----------
A          a
a          A

(2 行受影响)
*/

select *
from tb
where val = 'a' collate Chinese_PRC_CS_AI or vc = 'b' collate Chinese_PRC_CS_AI

/*
val        vc
---------- ----------
a          A

(1 行受影响)
*/

drop table tb