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MySQL中比like语句更高效的写法locatepositioninstrfind_in_set_MySQL

WBOY
WBOYOriginal
2016-06-01 13:00:091074browse
你是否一直在寻找比MySQL的LIKE语句更高效的方法的,下面我就为你介绍几种。

LIKE语句
SELECT `column` FROM `table` where `condition` like`%keyword%'

事实上,可以使用 locate(position) 和 instr这两个函数来代替

LOCATE语句
SELECT `column` from `table` where locate(‘keyword’,`condition`)>0

或是 locate 的別名 position
POSITION语句
SELECT `column` from `table` where position(‘keyword’ IN`condition`)

或是
INSTR语句
SELECT `column` from `table` where instr(`condition`, ‘keyword’)>0

locate、position 和 instr 的差別只是参数的位置不同,同时locate多一个起始位置的参数外,两者是一样的。
mysql> SELECT LOCATE(‘bar’, ‘foobarbar’,5);

-> 7

速度上这三个比用 like 稍快了一点。



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~华丽的分割线~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
还要给大家介绍一个新成员,那就是find_in_set

find_in_set(str1,str2) 函数:返回str2中str1所在的位置索引,其中str2必须以","分割开。



表:

mysql> select * from region;


+----+-------------+


| id | name               |


+----+-------------+


|  1  | name1,nam2  |


|  2  | name1             |


|  3  | name3       |


|  4  | name2,name4 |


|  5  | name3,name5 |


+----+-------------+


5 rows in set (0.00 sec)



FIND_IN_SET语句

mysql> select * from test where find_in_set('name1',name);


+----+------------+


| id | name            |


+----+------------+


|  1  | name1,nam2 |


|  2  | name1      |


+----+------------+


2 rows in set (0.02 sec)

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