You ever find yourself with the need to copy SQL Server logins from one server to another? Maybe you are setting up a failover site, building a replacement server, setting up a reporting instance, or maybe you just want to backup the logins just in case. If you are using Windows Logins, this is a simple matter of scripting the login and applying it to the other server. Copying SQL Server Logins from one box to another is a bit trickier because SQL Server stores and manages the password. So just how do you copy the login and preserve the password? I am glad you asked.
Understanding Login Components
To successfully copy a login from one server to another, you will need to ensure that the copy has the same SID and password. The link between database users and logins is done with the logins SID, if this is different on the new server than any databases you copy over will contain orphaned users. To ensure that both the SID and the password are the same, Microsoft has written a stored procedure to aid in our transfer.
SP_HELP_REVLOGIN
SP_HELP_REVLOGIN is a stored procedure that will return a complete list of the logins that exists on you SQL Server in a script that can be run to recreate them. This script does not exist on your SQL Server by default, you must create with the code provided by Microsoft in KB article 918992 here http://support.microsoft.com/kb/918992/. Once you have create the procedures you can easily generate the create statements that allow you to copy your logins.
As an example, I created a new login on my local instance of SQL Server called SQLScript with a password of scriptme. Now I can run SP_HELP_REVLOGIN as follows:
sp_help_revlogin 'SQLScript'
RESULTS:
/* sp_help_revlogin script
** Generated Oct 30 2007 9:23AM on laptop1 */
-- Login: SQLScript
CREATE LOGIN [SQLScript] WITH PASSWORD = 0x0100B642C5A8BC6778ECE4710ED3DC8D70E0EA31B6DF6B122756 HASHED, SID = 0x80525EB475F8414FB32D627BB876F213, DEFAULT_DATABASE = [master], CHECK_POLICY = OFF, CHECK_EXPIRATION = OFF
As you can see, I now have the syntax I need to recreate the login on another box. The SID will be forced to the same value and the passwords will match by virtue of this statement providing the hashed version of the password. If you need to copy all the logins, SQL Server and Windows Logins, you can run SP_HELP_REVLOGIN with no parameters.