The SQL for it is simply: ``` ATTACH DATABASE 'c:/sqlite/db/contacts.db' AS contacts; and in program terms: sqlite3_exec(pdb, "ATTACH DATABASE 'c:/sqlite/db/contacts.db' AS contacts;" ... ); ``` Which should all already work according to your given example, but note that: - attaching has to be allowed by your version of SQLite (or C# wrapper for it), - there are limits to how many DBs can be attached, - you need read/write privileges to the folder of the file you are attaching, - and to the DB file itself. (Depending on the Journal mode and intended use.) To get rid of it again you can do: ``` DETACH DATABASE contacts; ```