問題描述
我試圖弄清楚如何根據 Firebase 中的子子節點過濾產品.
I am trying to figure out how to filter products based on their sub child nodes in Firebase.
我的設置如下:
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 products 下的每個子節點進行排序，然后僅返回值為 12345 的子節點.
This will order every child node under products by its author property and then return only the ones that have a value of 12345.
請參閱 Firebase 關于查詢的文檔.
這篇關于根據 Firebase 中的子子項過濾產品的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網！