public int insertDistrict(String string, int i, int i1, int i2) {
       try {

            Connection con = DB.getInstance().getConnection();
            String sql = "select IdG from Grad where IdG =" + i;
            Statement stm = con.createStatement();
            ResultSet r = stm.executeQuery(sql);
            if(r.next()){
            PreparedStatement ps = con.prepareStatement("insert into Opstina (naziv,x,y,IdG) values (?,?,?,?)");
            ps.setString(1, string);
            ps.setInt(2, i);
            ps.setInt(3, i1);
            ps.setInt(4, i2);

            ps.execute();
            ResultSet rs = ps.getGeneratedKeys();
            rs.next();
            return rs.getInt(1);
            }

            return -1;

        } catch (SQLException ex) {
            Logger.getLogger(jp140452_CityOperations.class.getName()).log(Level.SEVERE, null, ex);
            return -1;
        }