Question

我想查找属于用户的组。
并且我想查找属于某个组的用户。
（例如ManyToMany）

如何制作模型？

我尝试过：
[]是一个集合
{}是文档

users : [
  "uid1" {
   "name" : "jack",
   "age" : 22,
   "groups" : [1, 2]
   },
   "uid2" {
   "name" : "jack",
   "age" : 22,
   "groups" : [1, 2]
   },
  "uid2" {
   "name" : "hori",
   "age" : 21,
   "groups" : [3, 4]
   },
  "uid3" {
   "name" : "dora",
   "age" : 31,
   "groups" : [3]
   }
]



groups : [
  "1" {
   "title" : "science",
   "memberCount" : 22,
   "members" : ["uid1", "uid2", "uid3"]
    },
  "2" {
   "title" : "history",
   "memberCount" : 34,
   "members" : ["uid5", "uid7"]
    },
  "3" {
   "title" : "math",
   "memberCount" : 34,
   "members" : ["uid4", "uid8", "uid11"]
    },
  "4" {
   "title" : "english",
   "memberCount" : 52,
   "members" : ["uid2", "uid3", "uid7"]
    }
   ]

对吗？如果是，如何查询？

Answer 1

您应将[]中的集合“成员”更改为类型“数组”：

groups : [ // remain collection
  "1" {
   "title" : "science",
   "memberCount" : 22,
   "members" : ["uid1", "uid2", "uid3"] // not in collection but a real array Type
    }
]

然后您可以查询属于用户的组：

CollectionReference groupsRef = db.collection("groups");
groupsRef.whereArrayContains("members", "uid2");

更多详细信息：https://firebase.google.com/docs/firestore/query-data/queries#array-contains

数据库Firestore用户和组（ManyToMany）

1 个答案: