Jamal,
The .gdb file (file geodatabase) cannot be directly converted to a .mdf file (SQL Server database file). Instead, create a new geodatabase on the database server, then import or copy and paste the data from the file geodatabase to the geodatabase on the database server.
Regards,
-Kim
File geodatabase is an Esri storage format. It has nothing to do with Microsoft's SQL-Server
database structure. They are incompatible, in the same way that diesel fuel can't be used
by a gasoline engine.
- V