如何使用关系将node.js中的3个对象保存到parse.com

Question

我正在尝试使用node.js（v0.10.28，mac os x）将3个对象保存到parse.com。对象彼此有关系。

以下是关系：

我使用数据浏览器配置了类：

• 汽车（未通过脚本更新）
• 驱动器
• RES
• STASTO

我的目标是理解关系（是的，我在parse.com上阅读关于关系的文档，但我不能将它应用于这个简单的例子）。我的剧本将

1. 查询我想要的车（在parse.com上只有1个），
2. 然后它会为Car，Drives，Res和`StaSto
创建对象
3. 然后它将关联对象并在其中放入一些假值。
4. 最后，它会尝试保存它们。以下是脚本失败的错误：Failed to create new myRes, with error code: undefined。 myDrive被创建，即使它应该是要创建的最后一个元素，并且myRes的创建失败。

任何人都可以帮忙吗？或者还有其他更好的方法吗？

感谢。

这是我的剧本：

console.log("Starting");
// +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
// PARSE Classes!
// +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
var Parse = require('parse').Parse;
var parse_JSKey = "xxx";
var parse_AppKey = "xxx";
Parse.initialize(parse_AppKey, parse_JSKey);
// +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++



// +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
// PARSE Classes!
// +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
var Drives = Parse.Object.extend("Drives");
var StaSto = Parse.Object.extend("StaSto");
var Res = Parse.Object.extend("Res");
var Car = Parse.Object.extend("Car");
// +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++



// +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
// fake data
// +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
var myDriveData = {'distance':21, 'speed': 99};
var carID = "mrNQcPRNl4"; //already in parse.com!
var myStaSto_lat = 48.1333;
var myStaSto_lng = 11.5667;
// +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++



// +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
// insert into parse
// +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
//   --- query for the car
var carQuery = new Parse.Query(Car);
carQuery.get(carID, {
  success: function(result) {
    var thisCar = result;
//   --- create a new drive
    var myDrive = new Drives(); // created a new object, but empty
    myDrive.set('distance', myDriveData.distance);
    myDrive.set('speed', myDriveData.speed);
//   --- create a new StaSto
    var myStaSto = new StaSto();
    myStaSto.set('coord',new Parse.GeoPoint({latitude: myStaSto_lat, longitude: myStaSto_lng}));
    myStaSto.set('drive',myDrive);
//   --- create a new Res
    var myRes = new Res();
    myRes.set('drive',myDrive);
    myRes.set('car',thisCar);
    myRes.set('res',717);
    console.log(myRes);
//   --- ----> save them all
    myRes.save(null, {
      success: function(response) {
        // Execute any logic that should take place after the object is saved.
        console.log('saved myRes succesfully');
        myStaSto.save(null,{
          success: function(response){
            console.log('saved myStaSto succesfully');

            myDrive.save(null,{
              success: function(response){
                console.log('saved myDrive succesfully');

              },
              error: function(response,error){
                  console.log('Failed to create new myDrive, with error code: ' + error.description);
              }
            }); // end of myDrive.save

          },
          error: function(response,error){
              console.log('Failed to create new myStaSto, with error code: ' + error.description);
          }
        }); // end of myStaSto save
      },
      error: function(response, error) {
        // Execute any logic that should take place if the save fails.
        // error is a Parse.Error with an error code and description.
        console.log('Failed to create new myRes, with error code: ' + error.description);
      }
    }); // end of myRes.save
  },
  error: function(object, error) {
    console.log('error in car query: ' + error.code + " " + error.message);
  }
}); // end of car query.



// +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Answer 1

不要在'save.res周围看到你的代码有什么问题。您可能希望阅读parse promises tho ...

尝试以不太复杂的形式玩它。

尝试使用一个FK类型关系保存'res'，并在'res.drive'中说一个直值。

幸运的是，你得到一个很好的保存而不是'undef'错误然后......

您可以尝试将当前关系类型之一切换为指针，看看是否有效。

Answer 2

原来我的代码是正确的。出现错误是因为我在parse.com中将列设置为关系（参见图片）。

我把它改成了指针，瞧，它运作得很好。我必须承认，parse.com的JavaScript开发人员指南有点简短。