Column In Existing Custom table In MODX database

I am workin in my client project and he wants me to add a column in an existing custom table under the MODX database. I don't know how to do that. Can anyone please help me and tell me the way I can add columns in existing custom table in MODX database?

Please don't double post.

This isn't really a MODX question, it's a MySQL question:

http://support.hostgator.com/articles/specialized-help/technical/phpmyadmin/adding-a-column-to-a-database-table-in-phpmyadmin

If you are talking about how to add a new column to a xpdo-object and the same time to your table, this is very easy with help of the MIGX - packagemanager

If you have installed MIGX.
go to components/MIGX

put in the name of your package
Do 'load schema'
Add the new field to your schema
Do 'save schema'
Do 'Add fields'

This will create the new map-files and add the new field to your table.