How do you get SQLServerExpress to create users?

Running as Administrator on my machine, I can create databases just fine, but when I try to create a user it fails wit开发者_StackOverflow社区h this error message.

1> create user mark from login mark
2> go
Msg 15007, Level 16, State 1, Server ENDER\SQLEXPRESS, Line 1
'mark' is not a valid login or you do not have permission.

I'm using sqlcmd to do this.

You need to create the server login "mark" before creating a database user "mark"

e.g. For Windows Authentication

CREATE LOGIN [mark] FROM WINDOWS WITH DEFAULT_DATABASE=[master]

e.g. Or For SQL Server Authentication

CREATE LOGIN [mark] WITH PASSWORD=N'YourPassword', DEFAULT_DATABASE=[master], CHECK_EXPIRATION=OFF, CHECK_POLICY=OFF

Then once the login is created the following should work

CREATE USER [mark] FOR LOGIN [mark]

By the way to get a list of server logins this is the query that management studio uses

SELECT
log.name AS [Name],
CASE WHEN N'U' = log.type THEN 0 WHEN N'G' = log.type THEN 1 WHEN N'S' = log.type THEN 2 WHEN N'C' = log.type THEN 3 WHEN N'K' = log.type THEN 4 END AS [LoginType],
log.is_disabled AS [IsDisabled],
log.create_date AS [CreateDate]
FROM
sys.server_principals AS log
WHERE
(log.type in ('U', 'G', 'S', 'C', 'K') AND log.principal_id not between 101 and 255 AND log.name <> N'##MS_AgentSigningCertificate##')
ORDER BY
[Name] ASC