John Lowther points to some help to Set up a test company that has a copy of live company data by using SQL Server 7.0, SQL Server 2000, SQL Server 2005, SQL Server 2008, or SQL Server 2012
Set up a test company that has a copy of live company data by using SQL Server 7.0, SQL Server 2000, SQL Server 2005, SQL Server 2008, or SQL Server 2012 – Microsoft Dynamics GP DBA
SQL & DataInstall, Upgrade & Admin
Archived post from 2014. Dynamics GP and the links it points to have changed since; check current documentation before relying on version-specific steps.