Android : not getting data from "IN" query in android

I am trying to get result from two tables and i'm using IN query for this. My problem is that i'm not getting any value in cursor even i have correct data. What can be wrong with this???

public String getContactNameByNumber(String number) {

    //String filter = MySQLiteHelper.COLUMN_CNT_NICK_NAME + " LIKE '%" + number + "%'";
    number = number.substring(number.length() % 10);
    String sql = "SELECT "
            + MySQLiteHelper.COLUMN_CNT_NICK_NAME 
            + " FROM " 
            + MySQLiteHelper.TABLE_NAME_CONTACT 
            + " WHERE "
            + MySQLiteHelper.COLUMN_CNT_CONTACT_ID
            + " IN ( SELECT "
            + MySQLiteHelper.COLUMN_PHN_CONTACT_ID
            + " FROM "
            + MySQLiteHelper.TABLE_NAME_PHONE
            + " WHERE "
            + MySQLiteHelper.COLUMN_PHN_NUMBER 
            + " = ?"
            + " ) ";

    Log.e("getContactNameByNumber", sql);

    Cursor cursor = database.rawQuery(sql, new String[] { number +"%" });

    while (cursor.moveToNext()) {
        Log.e("getContactNameByNumber", "1");
        return cursor.getString(cursor.getColumnIndex(MySQLiteHelper.COLUMN_CNT_NICK_NAME));
    }
    // make sure to close the cursor
    cursor.close();
    return null;
}