javascript - 从 Parse 查询中获取指针数据

Question

我正在尝试通过 JavaScript SDK 从我的 Parse.com 数据库中查询数据，但是来自指针的数据未通过。

我的 Parse DB 中有三个相关类:Questions、Talks 和 _User。 Questions 类有指针列('questioning' 和 'talk')，指向提出问题的用户和提交问题的谈话。

代码如下所示:

 <script type="text/javascript">
  Parse.initialize("PARSE APP ID", "PARSE JS KEY");
  var Questions = Parse.Object.extend("Questions");

    function getPosts(){
      var query = new Parse.Query(Questions);
                query.equalTo("active", true);
                query.descending("CreatedAt");
                query.find({

        success: function (results){
          var output = "";
            for (var i in results){
                var talk = results[i].get("talk");
                var question = results[i].get("question");
                var questioning = results[i].get("questioning");
                var talk = results[i].get("talk");
                output += "<li>";
                output += "<h3>"+question+"</h3>";
                output += "<p>"+questioning+"</p>";
                output += "<p>"+talk+"</p>";
                output += "</li>";
            }
            $("#list-posts").html(output);
        }, error: function (error){
            console.log("Query Error:"+error.message);
        }
      });
    }


    getPosts();

输出看起来像这样:

Test Question 1

[object Object]

[object Object]

问题本身是正确的(测试问题 1)，但它显示的不是用户(或用户 ID)[object Object]。谈话也一样。知道如何检索和显示此信息吗？

谢谢!

Answer 1

很高兴找到一个组织良好的问题，包括数据模型的详细信息。它也有一个简单的答案:要访问指向的对象，您必须告诉查询 include 它们。因此，该建议以及代码中的更多要点:

// see point below about for..in array iteration
// strongly suggest underscorejs, that has loads of other features
var _ = require('underscore');

function getPosts(){
    var query = new Parse.Query(Questions);
    query.equalTo("active", true);

    // order by creation is default, and createdAt is spelled with a lowercase 'c'
    //query.descending("CreatedAt");

    // these will fix the problem in the OP
    query.include("questioning");
    query.include("talk");

    // its a good habit to start using the promise-returning
    // varieties of these functions
    return query.find();
}

function updatePostList() {
    getPosts().then(function (results) {
        var output = "";
        // most authors recommend against for..in on an array
        // also, your use of var i as the index into results is incorrect
        // for (var i in results){  <-- change this to use _.each
        _.each(results, function(result) {
            var talk = result.get("talk");
            var question = result.get("question");
            var questioning = result.get("questioning");
            output += "<li>";
            output += "<h3>"+question+"</h3>";
            output += "<p>"+questioning+"</p>";
            output += "<p>"+talk+"</p>";
            output += "</li>";
        });

        // a good example of the value of underscore, you could shorten
        // the loop above by using _.reduce

        $("#list-posts").html(output);
    }, function (error) {
        console.log("Query Error:"+error.message);
    });
}