DROP LOGIN (Transact-SQL)
Applies To: SQL Server 2014, SQL Server 2016 Preview
Topic Status: Some information in this topic is preview and subject to change in future releases. Preview information describes new features or changes to existing features in Microsoft SQL Server 2016 Community Technology Preview 2 (CTP2).
Removes a SQL Server login account.
Applies to: SQL Server (SQL Server 2008 through current version), Azure SQL Database, Azure SQL Data Warehouse Public Preview.
A login cannot be dropped while it is logged in. A login that owns any securable, server-level object, or SQL Server Agent job cannot be dropped.
You can drop a login to which database users are mapped; however, this will create orphaned users. For more information, see Troubleshoot Orphaned Users (SQL Server).