使MySQL查询区分大小写的实现方法

2023年 4月 20日 53.3k 0

1、一种方法是可以设置表或行的collation,使其为binary或case sensitive。在MySQL中,对于Column Collate其约定的命名方法如下: *_bin: 表示的是binary case sensitive collation,也就是说是区分大小写的

1、一种方法是可以设置表或行的collation,使其为binary或case sensitive。在MySQL中,对于Column Collate其约定的命名方法如下: *_bin: 表示的是binary case sensitive collation,也就是说是区分大小写的 *_cs: case sensitive collation,区分大小写 *_ci: case insensitive collation,不区分大小写 ########### # 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、另外一种方法 ########### # 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、还有一种方法就是在查询时指定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)

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