It looks like SDF to MDF is some kind of database conversion which should be doable with a database management software or dedidcated conversion tool. Should be pretty straightforward database to database conversion.
Convert SQL Server compact edition database to Microsoft SQL Server master database file format.
We found 2 software records in the database related to .sdf to .mdf file format conversion.
Microsoft Windows software - convert sdf to mdf on Windows
Set of relation database tools for making and organization of SQL databases
Convert from sdf file format
The tables with software actions are a good pointer for what a certain program does with various file types and often may give users a good hint how to perform certain file conversion, for example the above-mentioned sdf to mdf. However, it is not perfect and sometimes can show results which are not really usable because of how certain programs work with files and the possible conversion is thus actually not possible at all.
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