替换all spaces：

UPDATE `table` SET `col_name` = REPLACE(`col_name`, ' ', '')

删除所有tabs字符：

UPDATE `table` SET `col_name` = REPLACE(`col_name`, '\t', '' )

删除所有new line字符：

UPDATE `table` SET `col_name` = REPLACE(`col_name`, '\n', '')

http://dev.mysql.com/doc/refman/5.0/zh-CN/string-
functions.html#function_replace

删除first and last space(s)列：

UPDATE `table` SET `col_name` = TRIM(`col_name`)

http://dev.mysql.com/doc/refman/5.0/zh-CN/string-
functions.html#function_trim