MySQL TRIM()函数的作用是什么？
MySQLTRIM()函数用于从字符串中删除特定的后缀或前缀或两者。TRIM()函数的工作原理可以借助其语法来理解-
语法
TRIM([{BOTH | LEADING | TRAILING} [str_to_remove] FROM] string)这里，
参数BOTH表示要从字符串中删除的左右前缀。
LEADING参数表示只删除前导前缀。
TRAILING参数表示仅删除尾随前缀。
Str_to_remove是参数，表示要从字符串中删除的字符串。
字符串参数表示必须从中删除前缀的字符串。
示例
mysql> Select TRIM(BOTH '0' FROM '0100'); +----------------------------+ | TRIM(BOTH '0' FROM '0100') | +----------------------------+ | 1 | +----------------------------+ 1 row in set (0.00 sec) mysql> Select TRIM(BOTH '**' from '**nhooo.com**'); +------------------------------------------------+ | TRIM(BOTH '**' from '**nhooo.com**') | +------------------------------------------------+ | nhooo.com | +------------------------------------------------+ 1 row in set (0.00 sec) mysql> Select TRIM(Trailing '**' from '**nhooo.com**'); +----------------------------------------------------+ | TRIM(Trailing '**' from '**nhooo.com**') | +----------------------------------------------------+ | **nhooo.com | +----------------------------------------------------+ 1 row in set (0.00 sec) mysql> Select TRIM(Leading '**' from '**nhooo.com**'); +---------------------------------------------------+ | TRIM(Leading '**' from '**nhooo.com**') | +---------------------------------------------------+ | nhooo.com** | +---------------------------------------------------+ 1 row in set (0.00 sec)