Is it a good idea to create a DLL API for DB connection + DB query
calls?

I guess it's the same for creating it in VC++ static library?

so my DLL will have API in header file like

connectSQLServer(){
SQLConnection sql = new SQLConnection();
}

getProgramForTVChannel ( String Channel, Time TimePeriod ){
// do the query for DB
}

searchProgram ( String Keyword ){
// do some DB query and return result
}

.... and other DLL API function for DB query