标题: MYSQL大小写的约定 [打印本页] 作者: sohu2000000 时间: 2008-05-10 17:15 标题: MYSQL大小写的约定 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)
注：WINDOWS系统不用修改，系统默认就是1
LINUX 系统默认是0。因为LINUX下的脚本都是区分大小写的。