如何在firestore中处理promise [英] How to handle promise in firestore

问题描述

这是我的代码，用于检查 collections

here is my code to check a doc is there in the collections

this.shopCollection = this.afs.collection<Shop>('shops', ref => {
  return ref.where('fulladdress', '==', myString)
});

我不知道为什么我不能在这个方法中使用 .then() 和 .catch() .当我传递一个字符串进行查询时，如果没有找到结果，我怎么知道?

i don't know why i can't use .then() and .catch() with this method. When i pass a string to query and if no result found how i know?

我正在使用 angularfire2 版本 ^5.0.0-rc.1 和 angular ^4.2.4 和 firebase ^4.5.0.

I am using angularfire2 version ^5.0.0-rc.1 with angular ^4.2.4 and firebase ^4.5.0.

请帮忙.

推荐答案

我得到了一些更改

这是我的代码

this.afs.collection<Shop>('shops').ref.where('fulladdress', '==', myString)
      .get()
      .then(res => {
        if(res.docs.length == 0){
          //no documents found
        }else{
          //you got some documents
          res.forEach(shop => {
            console.log(shop.id);
            console.log(shop.data());
          })
        }
      }).catch(err => {
        console.log('something went wrong '+ err)
      });

我不确定这是正确的方法，对我来说效果很好.

i am not sure this is the right way, works fine for me.

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