mongodb中1.新建一个数据库javamongotest 2.新建两个集合（user和owner），信息如下，要求：同时插入多个文档（insertMany） { "name" : “xiuxiu", "hobby" : "piano", “times”:6 } { "name" : chongyu", "hobby" : "basketball", “times”:5 } { "name" : "ruizhi", "hobby" : "books" “times”:3 }, { "name" :” yixin", "hobby" : " drawing" “times”:4 } { "name" : “yufeng", "hobby" : "music" “times”:6 } 2.向student集合插入如下文档 { "name" : “kefan", "hobby":”cloud computing”, times:1 } 3.统计文档user集合中的文档数量 4.查询name为kefan的文档，添加一个hobby属性 "likes":”helping others” 5.使用{name:"科凡"} 替换 name 为kefan 的文档 6.查询times>=5的user信息,并删除

1.新建一个数据库javamongotest并新建两个集合（user和owner），并同时插入多个文档（insertMany）

// 连接数据库
conn = new Mongo();
db = conn.getDB("javamongotest");

// 新建集合user并插入多个文档
db.user.insertMany([
  {
    "name": "xiuxiu",
    "hobby": "piano",
    "times": 6
  },
  {
    "name": "chongyu",
    "hobby": "basketball",
    "times": 5
  },
  {
    "name": "ruizhi",
    "hobby": "books",
    "times": 3
  },
  {
    "name": "yixin",
    "hobby": "drawing",
    "times": 4
  },
  {
    "name": "yufeng",
    "hobby": "music",
    "times": 6
  }
]);

// 新建集合owner并插入多个文档
db.owner.insertMany([
  {
    "name": "jack",
    "age": 28,
    "phone": "123456789"
  },
  {
    "name": "tom",
    "age": 35,
    "phone": "987654321"
  },
  {
    "name": "lucy",
    "age": 25,
    "phone": "135792468"
  }
]);

2.向student集合插入如下文档

db.student.insertOne({
  "name": "kefan",
  "hobby": "cloud computing",
  "times": 1
});

3.统计文档user集合中的文档数量

db.user.count();

4.查询name为kefan的文档，添加一个hobby属性"likes":”helping others”

db.student.updateOne(
  { "name": "kefan" },
  { $set: { "likes": "helping others" } }
);

5.使用{name:"科凡"} 替换 name 为kefan 的文档

db.student.replaceOne(
  { "name": "kefan" },
  { "name": "科凡", "hobby": "cloud computing", "times": 1 }
);

6.查询times>=5的user信息，并删除

db.user.find({ "times": { $gte: 5 } }).forEach(function(doc) {
  db.user.deleteOne({ "_id": doc._id });
});