如何从 Firebase 实时数据库中选择数据

Question

我有一个结构大致类似的数据库

// An index to track Ada's memberships
{
  "users": {
    "alovelace": {
      "name": "Ada Lovelace",
      // Index Ada's groups in her profile
      "groups": {
         // the value here doesn't matter, just that the key exists
         "techpioneers": true,
         "womentechmakers": true
      }
    },
    ...
  },
  "groups": {
    "techpioneers": {
      "name": "Historical Tech Pioneers",
      "members": {
        "alovelace": true,
        "ghopper": true,
        "eclarke": true
      }
    },
    ...
  }
}

但我不知道如何选择属于同一组成员的用户

Answer 1

您必须定义一个额外的 group_combinations 或 all_groups 索引，将每个用户存储在他们组合的组下：

all_groups: {
  "techpioneers_womentechmakers": {
    alovelace: true
  }
}