I was working with a database today that has a 'longint' data type. This type doesn't exist in the list in Poco::Data::SQLite::Utility::getColumnType, so it's just impossible to query that DB. The fix is to add the type to the getColumnType function:
_types.insert(TypeMap::value_type("LONGINT", MetaColumn::FDT_INT64));
Honestly, there's no documentation I could find on the internet regarding longint, and I'm just guessing from the name it's an int64 (and it most probably is). Adding the line to getColumnType fixes the issue.