public class BikeHistProvider extends ContentProvider {

// Contract
public final class Contract {
    public static final String KEY_ID = "_id";
    public static final String KEY_NAME = "name";
    /** Calculated at run time */
    public static final String KEY_MY_TRANSIENT_FIELD = "myTransientField";
}

@Override
public Cursor query(Uri uri, String[] projection,
                    String selection, String[] selectionArgs,
                    String sortOrder) {

    // Create a Cursor with the field structure defined in
    // Contract
    MatrixCursor mc = new MatrixCursor(new String[]{
        Contract.KEY_ID,
        Contract.KEY_NAME
        Contract.KEY_MY_TRANSIENT_FIELD
        });

    // Apply the query to the underlying database.
    Cursor c = qb.query(db, projection, selection, selectionArgs,
                null, null, orderBy);

    //Move result to MatrixCursor and add transient fields
    c.moveToFirst();
    do {
        //Create new entries
        Object[] values = {
        c.getInt(0), //The key for the database entry
        c.getString(Contract.KEY_NAME),
        calculateTransientField()};

        mc.addRow(values);
    } while (c.moveToNext());
    c.close();

    return mc;
    }
}