【MYSQL】查詢不區分大小寫
MYSQL在預設的情況下查詢是不區分大小寫的,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對這個表,預設情況下,下面兩個查詢的結果是一樣的:
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) |
如果想讓MYSQL知道你輸入的字母是大寫還是小寫的,修改表:
|
如果你只是想在SQL語句中實現的話:
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)
如果不想這麼麻煩而想服務一開啟就讓大小寫一致的話:
可以修改my.ini或者my.cnf
[mysqld]
lower_case_table_names=1
(0:區分;1:不區分)
然後重啟MYSQL服務。
mysql> show variables like '%case_table%';
+------------------------+-------+
| Variable_name | Value |
+------------------------+-------+
| lower_case_table_names | 1 |
+------------------------+-------+
1 row in set (0.00 sec)
注:WINDOWS系統不用修改,系統預設就是1
LINUX 系統預設是0。因為LINUX下的指令碼都是區分大小寫的。
http://www.blogjava.net/brock/archive/2009/04/17/266168.html
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