Firebase推送到具有对象数组的数据库

James B 发表于 Dev

詹姆斯·B

firebase数据库push方法使用唯一键将对象添加到数据库子级，例如，

postsRef.push({
  author: "gracehop",
  title: "Announcing COBOL, a New Programming Language"
});

将类似以下内容的内容放入数据库

"posts": {
    "-JRHTHaIs-jNPLXOQivY": {
      "author": "gracehop",
      "title": "Announcing COBOL, a New Programming Language"
    }

但是，如果我对对象数组使用push方法，例如

    postsRef.push({
        {
          author: "gracehop1",
          title: "Announcing COBOL, a New Programming Language"
        },
        {
          author: "gracehop2",
          title: "Announcing COBOL, a New Programming Language"
        }});

我得到一个唯一的键，其中包含数据库中的枚举对象，即

"posts": {
    "-JRHTHaIs-jNPLXOQivY": {
      "0": { 
         "author": "gracehop1",
         "title": "Announcing COBOL, a New Programming Language"
       },
      "1": {
         "author": "gracehop2",
         "title": "Announcing COBOL, a New Programming Language"
       }
     }}

有没有办法push在单个事务中处理对象数组，以便为数组中的每个对象获取唯一的键，即结果看起来像

"posts": {
        "-JRHTHaIs-jNPLXOQivY": {
             "author": "gracehop1",
             "title": "Announcing COBOL, a New Programming Language"
         "-JRHTHaIs-jNPLXOQivZ": {
             "author": "gracehop2",
             "title": "Announcing COBOL, a New Programming Language"
           }
         }}

弗兰克·范普菲伦

一个鲜为人知的事实是，您可以在push()不带任何参数的情况下进行调用，它只会为您生成一个位置/推送ID。通过该更新和多位置更新（请参阅此处和此处），您可以执行以下操作：

var key1 = postsRef.push().key;
var key2 = postsRef.push().key;
var updates = {};
updates[key1] = {
      author: "gracehop1",
      title: "Announcing COBOL, a New Programming Language"
    };
updates[key2] = {
      author: "gracehop2",
      title: "Announcing COBOL, a New Programming Language"
    };
ref.update(updates);

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