If you want to change the name of an existing database user, you can use the "ALTER USER" statement as shown in the tutorial exercise below:

-- Login with "sa"

USE GlobalGuideLineDatabase;

GO

ALTER USER ggl_User WITH NAME = Dba_User;

GO

-- List all user names

SELECT name, sid, type, type_desc

FROM sys.database_principals WHERE type = 'S';

GO

name    sid    type type_desc

-------------------- ------------------------ ---- ---------

dbo   0x01    S SQL_USER

guest   0x00    S SQL_USER

INFORMATION_SCHEMA NULL    S SQL_USER

sys   NULL    S SQL_USER

Dba_User   0x5EB8701EAEBAA74F86F... S SQL_USER

The of the last user changed from "ggl_User" to "Dba_User".