Node 和 MongoDB - 选择文档

要选择集合中的文档，可以使用collection.findOne()或 collection.find()方法来选择一个或多个文档。

database.collection("sampleCollection").findOne({}, function(error, result) {
   if (error) throw error;
   console.log(result);
});
database.collection("sampleCollection").find({}).toArray(function(error, result) {
   if (error) throw error;
   console.log(result);
});

例子

尝试以下示例来选择 mongodb 集合中的文档 -

将以下示例复制并粘贴为 mongodb_example.js -

const MongoClient = require('mongodb').MongoClient;
// Prepare URL
const url = "mongodb://localhost:27017/";
// make a connection to the database
MongoClient.connect(url, function(error, client) {
   if (error) throw error;
   console.log("Connected!");
   // Connect to the database
   const database = client.db('myDb');      
   database.collection("sampleCollection").findOne({}, function(error, result) {
      if (error) throw error;
      console.log(result);
   });   database.collection("sampleCollection").find({}).toArray(function(error, result) {
      if (error) throw error;
      console.log(result);
   });   
   // close the connection
   client.close();
});

输出

使用 Node 执行 mysql_example.js 脚本并验证输出。

node mongodb_example.js
Connected!
{
  _id: 60c4bbb40f8c3920a0e30fdd,
  First_Name: 'Radhika',
  Last_Name: 'Sharma',
  Date_Of_Birth: '1995-09-26',
  e_mail: 'radhika_sharma.123@gmail.com',
  phone: '9000012345'
}
[
  {
    _id: 60c4bbb40f8c3920a0e30fdd,
    First_Name: 'Radhika',
    Last_Name: 'Sharma',
    Date_Of_Birth: '1995-09-26',
    e_mail: 'radhika_sharma.123@gmail.com',
    phone: '9000012345'
  },
  {
    _id: 60c4bbb40f8c3920a0e30fde,
    First_Name: 'Rachel',
    Last_Name: 'Christopher',
    Date_Of_Birth: '1990-02-16',
    e_mail: 'rachel_christopher.123@gmail.com',
    phone: '9000054321'
  },
  {
    _id: 60c4bbb40f8c3920a0e30fdf,
    First_Name: 'Fathima',
    Last_Name: 'Sheik',
    Date_Of_Birth: '1990-02-16',
    e_mail: 'fathima_sheik.123@gmail.com',
    phone: '9000012345'
  },
  {
    _id: 60c4bbb40f8c3920a0e30fdc,
    First_Name: 'Mahesh',
    Last_Name: 'Parashar',
    Date_Of_Birth: '1990-08-21',
    e_mail: 'mahesh_parashar.123@gmail.com',
    phone: '9034343345'
  }
]