使MySQL查詢區分大小寫的實現方法

JenBurleson 8年前發布 | 7K 次閱讀 MySQL 數據庫服務器

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>

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