我正在尝试创建一个推文克隆以学习使用Firebase,我很想得到关于如何创建数据库结构的建议。我最关心的是关注关注者以及如何在关注500个用户时创建时间表。您需要执行500个查询并以某种方式对日期时间进行排序。
{
"followers" : {
"cesar" : {
"followers" : {
"cesar2" : true
},
"following" : {
"cesar2" : true
}
},
"cesar2" : {
"followers" : {
"cesar" : true
},
"following" : {
"cesar" : true
}
}
},
"tweet" : {
"cesar" : [ null, {
"content" : "tweet 1"
} ]
},
"users" : {
"cesar" : {
"name" : "César",
"notifications" : true,
"username" : "cesar"
},
"cesar2" : {
"name" : "César2",
"notifications" : false,
"username" : "cesar2"
}
}
}
答案 0 :(得分:9)
请参阅Firebase的开源Twitter克隆Firefeed。它包含它使用的walkthrough数据结构,归结为在发布新消息时使用扇出方法。以下是使用的规则的副本,它描述了基础数据结构:
{
"rules": {
// All data is readable by anyone.
".read": true,
"people": {
// A list of users with their names on the site.
"$userid": {
// Only the user can write their own entry into this list.
".write": "$userid ==auth.uid"
}
},
"users": {
"$userid": {
// The user is allowed to write everything in their bucket.
".write": "$userid ==auth.uid",
"following": {
// The following list should only contain actual ids from the "people" list.
"$followingid": {
".validate": "root.child('people').hasChild($followingid)"
}
},
"followers": {
// Anyone can add themself to to this user's followers list.
"$followerid": {
".write": "$followerid ==auth.uid"
}
},
"feed": {
"$sparkid": {
// User A can write in user B's feed, but only if A is following B, and only for sparks for which they are the author.
".write": "root.child('users/' + $userid + '/following').hasChild(auth.uid) && root.child('sparks/' + $sparkid + '/author').val() ==auth.uid"
}
}
}
},
"sparks": {
// A global list of sparks (the "firehose").
"$sparkid": {
// Modifying an existing spark is not allowed.
".write": "!data.exists()",
// Every spark should have an author and a body.
".validate": "newData.hasChildren(['author', 'content'])",
// A user can attribute a spark only to themselves.
"author": {
".validate": "newData.val() ==auth.uid"
},
"content": {
".validate": "newData.isString()"
}
}
},
"recent-users": {
// Users can add themselves to the list of users with recent activity.
"$userid": {
".write": "$userid ==auth.uid"
}
},
"recent-sparks": {
// Authors of sparks can add their sparks to this list.
"$sparkid": {
".write": "root.child('sparks/' + $sparkid + '/author').val() ==auth.uid"
}
},
"search": {
"firstName": {
"$searchKey": {
".write": "auth != null && (root.child('people/' +auth.uid + '/firstName').val() + '|' + root.child('people/' +auth.uid + '/lastName').val() + '|' +auth.uid) == $searchKey && newData.val() ==auth.uid"
}
},
"lastName": {
"$searchKey": {
".write": "auth != null && (root.child('people/' +auth.uid + '/lastName').val() + '|' + root.child('people/' +auth.uid + '/firstName').val() + '|' +auth.uid) == $searchKey && newData.val() ==auth.uid"
}
}
}
}
}