使MySQL查詢區分大小寫的實現方法
來自: http://blog.csdn.net//jiao_fuyou/article/details/40505573
1、一種方法是可以設置數據庫、表或行的collation,使其為binary或case sensitive。在MySQL中,對于Column Collate其約定的命名方法如下:
注意:如果表已經建立并且有數據,原來又沒有區分大小寫,這時alter table是沒用的,只能更新列的屬性
_bin: 表示的是binary case sensitive collation,也就是說是區分大小寫的
_cs: case sensitive collation,區分大小寫
*_ci: case insensitive collation,不區分大小寫
#####
Start binary collation example
#####
mysql> create table case_bin_test (word VARCHAR(10)) CHARACTER SET latin1 COLLATE latin1_bin;
Query OK, 0 rows affected (0.02 sec)
mysql> INSERT INTO case_bin_test VALUES ('Frank'),('Google'),('froogle'),('flickr'),('FlicKr');
Query OK, 5 rows affected (0.00 sec)
Records: 5 Duplicates: 0 Warnings: 0
mysql> SELECT FROM case_bin_test WHERE word LIKE 'f%';
+---------+
| word |
+---------+
| froogle |
| flickr |
+---------+
2 rows in set (0.00 sec)
mysql> SELECT FROM case_bin_test WHERE word LIKE 'F%';
+---------+
| word |
+---------+
| Frank |
| FlicKr |
+---------+
4 rows in set (0.00 sec)
#####
End
#####
2、另外一種方法
#####
Start case sensitive collation example
#####
mysql> create table case_cs_test (word VARCHAR(10)) CHARACTER SET latin1 COLLATE latin1_general_cs;
Query OK, 0 rows affected (0.08 sec)
mysql> INSERT INTO case_cs_test VALUES ('Frank'),('Google'),('froogle'),('flickr'),('FlicKr');
Query OK, 5 rows affected (0.00 sec)
Records: 5 Duplicates: 0 Warnings: 0
mysql> SELECT FROM case_cs_test WHERE word LIKE 'F%';
+---------+
| word |
+---------+
| Frank |
| FlicKr |
+---------+
4 rows in set (0.00 sec)
mysql> SELECT FROM case_cs_test WHERE word LIKE 'f%';
+---------+
| word |
+---------+
| froogle |
| flickr |
+---------+
2 rows in set (0.00 sec)
#####
end
#####
3、還有一種方法就是在查詢時指定collation
mysql> create table case_test (word VARCHAR(10)) CHARACTER SET latin1;
Query OK, 0 rows affected (0.01 sec)
mysql> INSERT INTO case_test VALUES ('Frank'),('Google'),('froogle'),('flickr'),('FlicKr');
Query OK, 7 rows affected (0.01 sec)
Records: 7 Duplicates: 0 Warnings: 0
mysql> SELECT FROM case_test WHERE word LIKE 'f%';
+---------+
| word |
+---------+
| Frank |
| froogle |
| flickr |
| FlicKr |
+---------+
6 rows in set (0.01 sec)
mysql> SELECT FROM case_test WHERE word LIKE 'F%';
+---------+
| word |
+---------+
| Frank |
| froogle |
| flickr |
| FlicKr |
+---------+
6 rows in set (0.01 sec)
mysql> SELECT FROM case_test WHERE word COLLATE latin1_bin LIKE 'F%';
+---------+
| word |
+---------+
| Frank |
| FlicKr |
+---------+
4 rows in set (0.05 sec)
mysql> SELECT FROM case_test WHERE word COLLATE latin1_bin LIKE 'f%';
+---------+
| word |
+---------+
| froogle |
| flickr |
+---------+
2 rows in set (0.00 sec)
mysql> SELECT FROM case_test WHERE word LIKE 'f%' COLLATE latin1_bin;
+---------+
| word |
+---------+
| froogle |
| flickr |
+---------+
2 rows in set (0.00 sec)
mysql> SELECT FROM case_test WHERE word LIKE 'F%' COLLATE latin1_bin;
+---------+
| word |
+---------+
| Frank |
| FlicKr |
+---------+
4 rows in set (0.01 sec)
mysql> SELECT * FROM case_test WHERE word LIKE 'F%' COLLATE latin1_general_cs;
+---------+
| word |
+---------+
| Frank |
| FlicKr |
+---------+
4 rows in set (0.04 sec)</span></span>