The Ember Data store provides a simple interface for finding records of a single type through the store object’s find method. Internally, the store uses find, findAll, and findQuery based on the supplied arguments. The first argument to store.find() is always the record type. The optional second argument determines if a request is made for all records, a single record, or a query.

Ember Data仓库提供了一个非常简单的查询一类记录的接口，该接口就是store对象的find方法。在内部，store根据传入的参数使用find、findAll和findQuery完成查询。store.find()的第一个参数是记录的类型，第二个可选参数确定查询是获取所有记录，还是一条记录，还是特定的记录。

Finding All Records of a Type

查询一个类型的所有记录

  1. var posts = this.store.find('post');

To get a list of records already loaded into the store, without making another network request, use all instead.

如果希望获取已经加载到仓库中的记录的列表，而不希望通过一个网络请求去获取，可以使用all方法。

  1. var posts = this.store.all('post'); // => no network request

find returns a DS.PromiseArray that fulfills to a DS.RecordArray and all directly returns a DS.RecordArray.

find会返回一个将使用DS.RecordArray来履行的DS.PromiseArray，而all直接返回DS.RecordArray。

It’s important to note that DS.RecordArray is not a JavaScript array. It is an object that implements Ember.Enumerable. This is important because, for example, if you want to retrieve records by index, the [] notation will not work—you’ll have to use objectAt(index) instead.

需要重点注意的一点是DS.RecordArray不是一个Javascript数组。它是一个实现了Ember.Enumerable的对象。这一点非常重要，因为例如希望通过索引获取记录，那么[]将无法工作，需要使用objectAt(index)来获取。

Finding a Single Record

查询一个记录

If you provide a number or string as the second argument to store.find(), Ember Data will attempt to retrieve a record of that with that ID. This will return a promise that fulfills with the requested record:

如果调用store.find()方法时，第二个参数是一个数字或者字符串，Ember Data将尝试获取对应ID的记录。find()方法将返回一个用请求的记录来履行的承诺。

  1. var aSinglePost = this.store.find('post', 1); // => GET /posts/1

Querying For Records

查询记录

If you provide a plain object as the second argument to find, Ember Data will make a GET request with the object serialized as query params. This method returns DS.PromiseArray in the same way as find with no second argument.

如果传递给find方法的第二个参数是一个对象，Ember Data会发送一个使用该对象来序列化出来的查询参数的GET请求。这是方法返回与不加第二个参数时候一样的DS.PromiseArray。

For example, we could search for all person models who have the name of Peter:

例如，可以查询名为Peter的person模型的所有记录：

  1. var peters = this.store.find('person', { name: "Peter" }); // => GET to /persons?name='Peter'

Integrating with the Route’s Model Hook

与路由的模型钩子集成

As discussed in Specifying a Route’s Model, routes are responsible for telling their template which model to render.

如同在指定路由的模型一节中讨论的一样，路由是负责告诉模板将渲染哪个模型。

Ember.Route‘s model hook supports asynchronous values out-of-the-box. If you return a promise from the model hook, the router will wait until the promise has fulfilled to render the template.

Ember.Route的model钩子支持立即可用的异步值。如果model钩子返回一个承诺，路由将等待承诺履行条件满足时才渲染模板。

This makes it easy to write apps with asynchronous data using Ember Data. Just return the requested record from the model hook, and let Ember deal with figuring out whether a network request is needed or not.

这使得使用Ember Data的异步数据来编写应用变得容易。只需要通过model钩子返回请求的记录，交给Ember来处理是否需要一个网络请求。

  1. App.Router.map(function() {
  2.   this.resource('posts');
  3.   this.resource('post', { path: ':post_id' });
  4. });
  6. App.PostsRoute = Ember.Route.extend({
  7.   model: function() {
  8.     return this.store.find('post');
  9.   }
  10. });
  12. App.PostRoute = Ember.Route.extend({
  13.   model: function(params) {
  14.     return this.store.find('post', params.post_id);
  15.   }
  16. });