Question

以下是firebase中我的类的结构：

{

  "groups" : {
    "-KjkdYVP3N69GaDfLwS1" : {
      "groupname" : "Ballet Class",
      "description" : "8 years onwards",
      "picture" : "assets/img/dance.jpg",
      "type" : "dance"
    },
    "-KjkdYVP3N69GaDfLwS2" : {
      "groupname" : "Ballet Class",
      "description" : "8 years onwards",
      "picture" : "assets/img/dance.jpg",
      "type" : "dance"
    },
    "-KjkdYVP3N69GaDfLwS3" : {
      "groupname" : "Ballet Class",
      "description" : "8 years onwards",
      "picture" : "assets/img/dance.jpg",
      "type" : "dance"
    },
    "-KjkdYVP3N69GaDfLwS4" : {
      "groupname" : "Ballet Class",
      "description" : "8 years onwards",
      "picture" : "assets/img/dance.jpg",
      "type" : "dance"
    }
  },

  "linking" : {
    "DCuf5MvTlpQa0LC4BoJWedIiFfc2" : {
      "groupid" : {
        "-KjkdYVP3N69GaDfLwS1" : true,
        "-KjkdYVP3N69GaDfLwS2" : true,
        "-KjkdYVP3N69GaDfLwS3" : true,
        "-KjkdYVP3N69GaDfLwS4" : true
      },
      "memberid" : {
        "-KjkdduprKpr8e0P7KH1" : true,
        "-KjkdduprKpr8e0P7KH2" : true,
        "-KjkdduprKpr8e0P7KH3" : true,
        "-KjkdduprKpr8e0P7KH4" : true

      },
      "role" : "admin",
      "uid" : "DCuf5MvTlpQa0LC4BoJWedIiFfc2"
    }
  },
}

我有2个课程，并且连接了＃39;和＆＃39;团体＆＃39;。一旦用户登录，我想从链接表中获取用户组的详细信息，并且还希望根据第一个查询的组ID返回来获取组详细信息。我独立编写了这两个查询：

从链接类中获取组： - this.groupid = this.af.database.list（＆＃39; / linking /＆＃39; + uid +＆＃39; groupid）;

获取群组的详细信息： this.groupdetails = this.af.database.list（＆＃39; / groups＆＃39; + this.groupid）;

但我知道这段代码无效。

有人可以建议正确的方法来处理这个要求吗？

我最终想在页面上显示组详情

<li  *ngFor="let group of groups| async">
               {{ (group.data | async)?.field }}

Answer 1

var groups = [];
this.af.database.object('linking/'+ uid).subscribe(linking=>{
linking.groupid.forEach(groupid=>{
 groups.push(this.af.database.list('/groups'+groupid));
})
})

这可以让您了解如何检索数据。干杯：）

使用Firebaselistobservable嵌套恢复数据

1 个答案: