Programmatically set a DB user to be db_owner

How can I assign the db_owner role to a user that I have created?

I am able to create a login and add them开发者_如何学JAVA to the database. I don't know how to change their permission to db_owner using a SQL query.

I have a feeling I am maybe missing something with my query where I add the user to the database?

Here is the query to add the user to the database

CREATE USER [Driver-SOC-ChrisTest] FOR LOGIN [Driver-SOC-ChrisTest] 
WITH DEFAULT_SCHEMA=[dbo]

To give the user DBO permissions:

EXEC sp_addrolemember N'db_owner', N'[Driver-SOC-ChrisTest]'

To make the user owner of the database (not advised):

EXEC sp_changedbowner N'[Driver-SOC-ChrisTest]'

I quite often go into the GUI, make the changes I need and then rather than saving by pressing OK, I press the Script button at the top of the dialog and send it to a new window.

This would give you the code the previous poster provided.