mysql字符类型默认是不区分大小写的,即select * from t where name='AAA'与='aaa'没区别,以下是测试的例子 (root)); (root,,,,'BbB'); (root@localhost)[hello]> select * from test1; +------+------+ | id | name | +------+------+ | aaa | | AAA | | bbb | | BbB | +------+------+ (root@local