Howto alter existing mysql table

commands run from mysql interactive prompt

Add new varchar column to the end of the table

 >ALTER TABLE `tablename_here` ADD `new_column_name` VARCHAR( 255 ) NOT NULL ;

Add new integer column after an existing column in table

 >ALTER TABLE `tablename_here` ADD `new_column_name` INT NOT NULL AFTER `existing_column` ;

This changes the column called "name" on the table called "people" to now allow 35 characters.

 >alter table people modify name VARCHAR(35) ; 

This removes the column "flavor" from the table called "icecream".

 >alter table icecream drop column flavor;