MongoDB - 将新文档插入现有文档

Question

我正在学习 MongoDB 的一些基础知识。我有一个来自 MongoDB 教程的文档：

>db.post.insert([
{
   title: 'MongoDB Overview',
   description: 'MongoDB is no sql database',
   by: 'tutorials point',
   url: 'http://www.tutorialspoint.com',
   tags: ['mongodb', 'database', 'NoSQL'],
   likes: 100
},
{
   title: 'NoSQL Database',
   description: 'NoSQL database doesn't have tables',
   by: 'tutorials point',
   url: 'http://www.tutorialspoint.com',
   tags: ['mongodb', 'database', 'NoSQL'],
   likes: 20,
 comments: [
   {
     user:'user1',
     message: 'My first comment',
     dateCreated: new Date(2013,11,10,2,35),
     like: 0
   }
]
}
])

如何在现有文档中插入新评论？谢谢

Answer 1

你必须使用 $push

db.coll.update({"title" : "NoSQL Database"},{$push:{"comments":{
     "user":'user2',
     "message": 'My second comment',
     "dateCreated": new Date(2013,11,10,2,35),
     "like": 0
   }}})