我正在嘗試使用GetGeneratedKey方法將剛創(chuàng)建的表ID作為一個整數(shù)返回。但這是行不通的。我的密碼    public int saveWorkout(String titel, String beschrijving, int categorie_id, int persoon_id) throws SQLException {    int result = 0;    try (Connection con = super.getConnection()) {        String query = "INSERT INTO \"Workout\" VALUES(?,?,?,?)";        String query2 = "INSERT INTO \"Workout_Oefening\" VALUES(?,?)";        PreparedStatement pstmt = con.prepareStatement(query);        pstmt.setString(1, titel);        pstmt.setString(2, beschrijving);        pstmt.setInt(3, persoon_id);        pstmt.setInt(4, categorie_id);        pstmt.executeUpdate();        ResultSet keys = pstmt.getGeneratedKeys();        if(keys.next()) {            result = keys.getInt(1);            System.out.println(keys.getInt(1));        }    } catch (SQLException sqle) {        sqle.printStackTrace();    }    return result;}它總是返回0！如果我打印keys.getint（1）它返回以下內(nèi)容org.apache.tomcat.dbcp.dbcp2.DelegatingResultSet@8a14f70