Firebase - 如何在列表查询中执行 where 项？

Question

给定

url根是：https://myApp.firebaseio.com

还有

数据是：

  {
    "users": {
      "u00001": {
        "name": "Andy",
        "teams": {
           "t001": true,
           "t003": true
        }
      },
      ...
    },
    "teams": {
      "t001": {
        "name": "Alpha Team"
      },
      "t002": {
        "name": "Beta Team"
      },
      "t003": {
        "name": "Gamma Team"
      },
      ...
    }
  }

和

Andy 加入的团队是 ['t001', 't003']

问题：

是否可以使用 ONE 查询来获取 Andy 加入的所有团队的名称？ （查找所有团队名称，其中 ID 在 ['t001', 't003'] 中，例如期望 ["Alpha Team", "Gamma Team"]）

提前致谢。

Answer 1

这应该可行：

var ref = new Firebase('https://myApp.firebaseio.com');
ref.child('users/u00001/teams').on('value', function(teamKeys) {
  var teamNames = [];
  teamKeys.forEach(function(teamKey) {
    ref.child('teams').child(teamKey.key()).once('value', function(teamSnapshot) {
      teamNames.push(teamSnapshot.val().name);
      if (teamNames.length == teamKeys.numChildren()) {
        console.log('All team names loaded');
      }
    }); 
  });
})

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Answer 2

var data = { "users": { "u00001": { "name": "Andy", "teams": { "t001": true, "t003": true } }, }, "teams": { "t001": { "name": "Alpha Team" }, "t002": { "name": "Beta Team" }, "t003": { "name": "Gamma Team" } } }

function getNames(data, user) {
    var res = [];
    var teams = [];
    Object.keys(data.users).forEach(k => {
        if (data.users[k].name == user) {
            Object.keys(data.users[k].teams).forEach(t => teams.push(t))
        }
    });
    Object.keys(data.teams).forEach(t => {
        if (teams.indexOf(t) > -1) {
            res.push(data.teams[t].name);
        }
    });
    return res;
}

document.write(JSON.stringify(getNames(data, "Andy")));