MySQL elimina todos los espacios en blanco de toda la columna

Para reemplazar all spaces :

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

Para eliminar todas las tabs caracteres :

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

Para eliminar todas las new line caracteres :

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

https://dev.mysql.com/doc /refman/5.0/en/string-functions.html#function_replace

Para eliminar first and last space(s) de la columna:

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

https://dev.mysql.com/doc /refman/5.0/en/string-functions.html#function_trim