問題描述

我試圖弄清楚如何根據(jù) Firebase 中的子子節(jié)點(diǎn)過濾產(chǎn)品.

I am trying to figure out how to filter products based on their sub child nodes in Firebase.

我的設(shè)置如下:

products/
     product1
        /author: 12345
        /title: "Awesome"
        /description: "more awesome"
     product2
        /author: 67890
        /title: "Awesome"
        /description: "more awesome"

如何查詢 Firebase 以便僅檢索它所持有的 child($productId).child(author) 等于 12345 的產(chǎn)品?

How can I query Firebase such that I retrieve only the products for which it holds that child($productId).child(author) equals 12345?

我嘗試了以下方法，但這顯然不起作用.我需要一種過濾子子項(xiàng)的方法:

I tried the following, but that obviously does not work. I need a way to filter on the subchild:

var ref = new Firebase(FBURL);

// Attach an asynchronous callback to read the data at our posts reference
ref.child("products").child('$productId').child('author').equalTo(12345).on("value", function(snapshot) {
      console.log(snapshot.val());
    }, function (errorObject) {
      console.log("The read failed: " + errorObject.code);
});

推薦答案

只需使用orderByChild():

ref.child("products").orderByChild('author').equalTo(12345)...

這將通過 author 屬性對(duì) products 下的每個(gè)子節(jié)點(diǎn)進(jìn)行排序，然后僅返回值為 12345 的子節(jié)點(diǎn).

This will order every child node under products by its author property and then return only the ones that have a value of 12345.

請(qǐng)參閱 Firebase 關(guān)于查詢的文檔.

這篇關(guān)于根據(jù) Firebase 中的子子項(xiàng)過濾產(chǎn)品的文章就介紹到這了，希望我們推薦的答案對(duì)大家有所幫助，也希望大家多多支持html5模板網(wǎng)！