欢迎您访问程序员文章站本站旨在为大家提供分享程序员计算机编程知识!
您现在的位置是: 首页  >  数据库

MySQL数据表中内容大小写区分的设置_MySQL

程序员文章站 2024-02-12 14:02:16
...
bitsCN.com

MySQL数据表中内容大小写区分的设置

MYSQL在默认的情况下查询是不区分大小写的,例如:

mysql> create table t1( -> name varchar(10)); Query OK, 0 rows affected (0.09 sec) mysql> insert into t1 values('you'),('You'),('YOU'); Query OK, 3 rows affected (0.05 sec) Records: 3 Duplicates: 0 Warnings: 0 

对这个表,缺省情况下,下面两个查询的结果是一样的:

mysql> select * from t1 where name = 'you'; +------+ | name | +------+ | you | | You | | YOU | +------+ 3 rows in set (0.00 sec) mysql> select * from t1 where name = 'YOU'; +------+ | name | +------+ | you | | You | | YOU | +------+ 3 rows in set (0.00 sec) 

如果想让MYSQL知道你输入的字母是大写还是小写的,修改表:

mysql> alter table t1 change name name varchar(10) binary; Query OK, 3 rows affected (0.20 sec) Records: 3 Duplicates: 0 Warnings: 0 mysql> select * from t1 where name = 'you'; +------+ | name | +------+ | you | +------+ 1 row in set (0.00 sec) mysql> select * from t1 where name = 'YOU'; +------+ | name | +------+ | YOU | +------+ 1 row in set (0.00 sec) 

如果你只是想在SQL语句中实现的话:

mysql> select * from t1 where name = binary 'YOU'; +------+ | name | +------+ | YOU | +------+ 1 row in set (0.02 sec) mysql> select * from t1 where name = binary 'you'; +------+ | name | +------+ | you | +------+ 1 row in set (0.00 sec) 

如果不想这么麻烦而想服务一开启就让大小写一致的话:

可以修改my.ini或者my.cnf

[mysqld] lower_case_table_names=1 (0:区分;1:不区分) 

然后重启MYSQL服务。

mysql> show variables like '%case_table%'; +------------------------+-------+ | Variable_name | Value | +------------------------+-------+ | lower_case_table_names | 1 | +------------------------+-------+ 1 row in set (0.00 sec)


bitsCN.com