Nodejs使用express连接数据库mongoose的示例

npm install mongoose

const mongodb = require('mongoose');

const mongoose = require('mongoose');

// mongoose连接字符串，包括数据库地址和名称
mongoose.connect('mongodb://localhost:27017/mydatabase')
    .then(() => {
        console.log('Connected to the database');
    })
    .catch((err) => {
        console.error('Failed to connect to the database:', err);
    });

const userValue =new mongoose.Schema({
    name: String,
    age: Number,
    email: String,
    password: String,
    phone: String,
    address: String,
    gender: String,
    dob: Date,
    createdAt: { type: Date, default: Date.now },
    updatedAt: { type: Date, default: Date.now }
});

const User = mongoose.model('User', userValue);

const mongoose = require('mongoose');

// MongoDB 连接字符串，包括数据库地址和名称
mongoose.connect('mongodb://localhost:27017/mydatabase')
    .then(() => {
        console.log('Connected to the database');
    })
    .catch((err) => {
        console.error('Failed to connect to the database:', err);
    });

const userValue =new mongoose.Schema({
    name: String,
    age: Number,
    email: String,
    password: String,
    phone: String,
    address: String,
    gender: String,
    dob: Date,
    createdAt: { type: Date, default: Date.now },
    updatedAt: { type: Date, default: Date.now }
});

const User = mongoose.model('User', userValue);

module.exports = { User };

const { User }= require('./db');

// 在连接成功后执行数据库操作
client.connect(err => {
  if (err) {
    console.error('Failed to connect to the database:', err);
    return;
  }
  console.log('Connected successfully to the database');

  const db = client.db();

  // 查询所有文档
  db.collection('mycollection').find().toArray((err, docs) => {
    if (err) {
      console.error('Error fetching documents:', err);
      return;
    }
    console.log('Documents:', docs);
  });

  // 插入文档
  db.collection('mycollection').insertOne({ name: 'John', age: 30 }, (err, result) => {
    if (err) {
      console.error('Error inserting document:', err);
      return;
    }
    console.log('Document inserted:', result.insertedId);
  });

  // 更新文档
  db.collection('mycollection').updateOne({ name: 'John' }, { $set: { age: 35 } }, (err, result) => {
    if (err) {
      console.error('Error updating document:', err);
      return;
    }
    console.log('Document updated:', result.modifiedCount);
  });

  // 删除文档
  db.collection('mycollection').deleteOne({ name: 'John' }, (err, result) => {
    if (err) {
      console.error('Error deleting document:', err);
      return;
    }
    console.log('Document deleted:', result.deletedCount);
  });
});

// 关闭数据库连接
client.close();