MySQL 字符类型大小写敏感

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@localhost)[hello]> create table test1(id int, name varchar(10));
(root@localhost)[hello]> insert into test1 values(1,'aaa'),(2,'AAA'),(3,'bbb'),(4,'BbB');
(root@localhost)[hello]> select * from test1;
+------+------+
| id | name |
+------+------+
| 1 | aaa |
| 2 | AAA |
| 3 | bbb |
| 4 | BbB |
+------+------+

(root@localhost)[hello]> select * from test1 where name = 'AAA';
+------+------+
| id | name |
+------+------+
| 1 | aaa |
| 2 | AAA |
+------+------+

(root@localhost)[hello]> select * from test1 where name = 'aaa';
+------+------+
| id | name |
+------+------+
| 1 | aaa |
| 2 | AAA |
+------+------+