I\'m trying to create a user with a login for a SSDT database project. The login already exists on the target server. With the following SQL:
CREATE USER [MyLogi
If you are guaranteed to have the login on the server, your best bet is to tweak your master dacpac file. There are some instructions on how to do this here: http://sqlproj.com/index.php/2013/02/how-to-add-objects-to-master-dacpac
Alternatively, you could remove references to logins from the SSDT portion and handle it in post-deploy scripts. If you have any sort of environment where different permissions need to be applied in different server (Development, QA, Production), that might be the better option. I've blogged about this here: http://schottsql.blogspot.com/2013/05/ssdt-setting-different-permissions-per.html
Hopefully one of those will help. I've actually used the first option to work around an issue with needing to use EXECUTE AS, which requires that the user is in the project. It was a little tricky to get the exact XML, but I worked around it by creating an empty project with just that login, building it, and copying the XML from the dacpac into the master dacpac.