如果你只是目前查询区分,那么还是不要这样改,免得又反悔,如此查询:
select * from a
/*
a_nam a_add
---------- ----------
1 aa
1 bb
2 cc
2 vv
2 kk
3 dd
3 ee
4 dd
5 ee
6 yy
6 yy
(11 row(s) affected)
*/
现在我们查询a_add = 'aa'的,'Aa'等等不行!
Example 1:
select * from a
where a_add collate Chinese_PRC_CS_AS_WS = 'aa'
/*
a_nam a_add
---------- ----------
1 aa
(1 row(s) affected)
*/
Example 2:
select * from a
where a_add collate Chinese_PRC_CS_AS_WS = 'Aa'
/*
a_nam a_add
---------- ----------
(0 row(s) affected)
*/
方法三.上面的记不住,那么就用最笨的方法,转化为ascii
select * from a
where
ascii(substring(a_add,1,1)) = ascii(substring('Aa',1,1))
and
ascii(substring(a_add,2,1)) = ascii(substring('Aa',2,1))
/*
a_nam a_add
---------- ----------
(0 row(s) affected)
*/
方法三:任何版本都可以
select * from a
where cast(a_add as varbinary(10))= cast('aa' as varbinary(10))