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MYSQL數(shù)據(jù)庫mysql trim函數(shù)用法實例

作者：VEPHP   時間 2017-09-27

《MYSQL數(shù)據(jù)庫mysql trim函數(shù)用法實例》要點：
本文介紹了MYSQL數(shù)據(jù)庫mysql trim函數(shù)用法實例，希望對您有用。如果有疑問，可以聯(lián)系我們。

導讀：一,mysql去除左空格函數(shù)：ltrim(str) returns the string str with leading space characters removed.例子： mysql> select lt...

一,mysql去除左空格函數(shù)：
ltrim(str)
returns the string str with leading space characters removed.MYSQL數(shù)據(jù)庫

例子：
?MYSQL數(shù)據(jù)庫

mysql> select ltrim(' barbar');
-> 'barbar'
this function is multi-byte safe.

二,mysql去除右空格函數(shù)：
rtrim(str)
returns the string str with trailing space characters removed.MYSQL數(shù)據(jù)庫

例子：
?MYSQL數(shù)據(jù)庫

mysql> select rtrim('barbar?? ');
-> 'barbar'MYSQL數(shù)據(jù)庫

this function is multi-byte safe.MYSQL數(shù)據(jù)庫

三,trim函數(shù)可以過濾指定的字符串：
完整格式：trim([{both | leading | trailing} [remstr] from] str)
簡化格式：trim([remstr from] str)MYSQL數(shù)據(jù)庫

returns the string str with all remstr prefixes or suffixes removed. if none of the specifiers both, leading, or trailing is given, both is assumed. remstr is optional and, if not specified, spaces are removed.MYSQL數(shù)據(jù)庫

例子：
?MYSQL數(shù)據(jù)庫

mysql> select trim(' bar?? '); //默認刪除前后空格
-> 'bar'
mysql> select trim(leading ',' from ',,barxxx'); //刪除指定首字符 如’,‘
-> 'barxxx'
mysql> select trim(both ',' from ',,bar,,,');? //刪除指定首尾字符
-> 'bar'
mysql> select trim(trailing ',' from 'barxxyz,,');
-> 'barxxyz'
?
mysql> select trim(' bar?? '); //默認刪除前后空格
-> 'bar'
mysql> select trim(leading ',' from ',,barxxx');? //刪除指定首字符 如’,‘
-> 'barxxx'
mysql> select trim(both ',' from ',,bar,,,');? //刪除指定首尾字符
-> 'bar'
mysql> select trim(trailing ',' from 'barxxyz,,');
-> 'barxxyz'
?
mysql> update table set `field`=trim(trailing ',' from `field`) where where `field` like '%,';
this function is multi-byte safe.

mysql trim函數(shù)清除字段兩邊的空格：
?MYSQL數(shù)據(jù)庫

update zen_products setproducts_additional_image=trim(products_additional_image) where 子句

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