The ALTER DATABASE command allows a database administrator to modify SQL Server databases and their files and filegroups. This includes permitting the changing of database configuration options. Why Read Only ? When you need to ensure that the data is a database is not modified by any users or automated processes, it is useful to set the database into a read-only mode. Once read-only, the data can be read normally but any attempts to create, updated or delete table rows is disallowed. This makes the read-only mode ideal when preparing for data migration, performing data integrity checking or when the data is only required for historical reporting purposes. Make Database Read Only USE [master] GO ALTER DATABASE [TESTDB] SET READ_ONLY WITH NO_WAIT GO Make Database Read/Write USE [master] GO ALTER DATABASE [TESTDB] SET READ_WRITE WITH NO_WAIT GO In case you get the following error message ...