How to calculate the SID for new logins?

Question

I want to create a number of database users on two sql server instances. To be able to easily copy databases from one instance to another, I want the SIDs to be consistent.

My idea was to use predictable SIDs, to minimize maintenance pain. I a dreaming about something like this:

CREATE LOGIN newuser1 WITH PASSWORD = '...', SID = CAST('newuser1' AS BINARY(16))

-- or alternatively:
CREATE LOGIN newuser1 WITH PASSWORD = '...', SID = HASHBYTES('newuser1')

Calculating values for the SID, however, seems not to be supported by the CREATE LOGIN command:

Meldung 102, Ebene 15, Status 1, Zeile 1
Falsche Syntax in der Nähe von "SID". -- Wrong syntax near "SID"

How can I use a calculated value for SID?

Answer 1

This can be accomplished by assembling the sql statement in a variable and the executing it with sp_executesql:

DECLARE @SQL nvarchar(4000)

SET @SQL = 'CREATE LOGIN newuser1 WITH PASSWORD = ''...'', SID = 0x'+CONVERT(VARCHAR(1000), CAST('newuser1' AS binary(16)), 2)
PRINT @SQL
EXEC sp_executesql @SQL

Alternatively, if you want to reuse this approach, you can use create a stored procedure:

CREATE PROCEDURE create_user_with_predictable_sid
    @UserName varchar(256),
    @Password varchar(256)
AS
DECLARE @SQL nvarchar(4000) = 'CREATE LOGIN '+@UserName+' WITH PASSWORD = '''+@Password+''', SID = 0x'+CONVERT(VARCHAR(1000), CAST(@UserName AS binary(16)), 2)
PRINT @SQL
EXEC sp_executesql @SQL
GO  

GO

create_user_with_predictable_sid 'newuser1', '...'
GO

DROP PROCEDURE create_user_with_predictable_sid