mongoose数据库操作

const mongoose = require('mongoose');
// 1. 连接数据库
mongoose.connect('mongodb://localhost:27017/m_data', {useNewUrlParser: true});
mongoose.connection.on('open', ()=>{
    console.log('数据库连接成功！');
});
// 2. 监听数据库的各种状态
let db = mongoose.connection;

// 3. 监听
// 3.1 连接成功
db.on('open', ()=>{
    console.log('数据库连接成功！');
});

// 3.2 连接失败
db.on('error', ()=>{
    console.log('数据库连接失败！');
});

// 3.3 断开连接
db.on('close', ()=>{
    console.log('数据库断开连接！');
});

const mongoose = require('mongoose');
mongoose.connect('mongodb://localhost:27017/m_data', {useNewUrlParser: true});
mongoose.connection.on('open', ()=>{
    console.log('数据库连接成功！');
});

// 2. 创建模式对象
let Schema = mongoose.Schema;
let personSchema = new Schema({
    name: String,
    age: Number,
    chat: String,
    sex: {
        type: String,
        default: '男'
    }
});

// 3. 创建Model集合对象
let personModel = mongoose.model('person', personSchema);

// 4. 往集合中插入文档
/*
personModel.create({
    name: '小撩',
    age: 25,
    chat: 'itlike001',
    sex: '男'
}).then((data)=>{
    console.log(data);
}).catch((err)=>{
    console.log(err);
});
*/

/*
personModel.create({
    name: '谢霆锋',
    age: 39,
    chat: 'xtf1990',
    sex: '男'
}).then((data)=>{
    console.log(data);
}).catch((err)=>{
    console.log(err);
});
*/

personModel.create([
    {name: '王菲', age: 49, chat: 'xtf1990', sex: '女'},
    {name: '李宇春', age: 29, chat: 'lyc', sex: '女'},
    {name: '周杰伦', age: 36, chat: 'zjl'},
    {name: '宋小宝', age: 50, chat: 'sxb'},
    {name: '赵薇', age: 60, chat: 'zw', sex: '女'},
]).then((data)=>{
    console.log(data);
}).catch((err)=>{
    console.log(err);
});

const mongoose = require('mongoose');
mongoose.connect('mongodb://localhost:27017/m_data', {useNewUrlParser: true});
mongoose.connection.on('open', ()=>{
    console.log('数据库连接成功！');
});

// 2. 创建模式对象
let Schema = mongoose.Schema;
let personSchema = new Schema({
    name: String,
    age: Number,
    chat: String,
    sex: {
        type: String,
        default: '男'
    }
});

// 3. 创建Model集合对象
let personModel = mongoose.model('person', personSchema);

// 4. CRUD
// 4.1 增加
/*personModel.insertMany([
    {name: '王菲', age: 49, chat: 'xtf1990', sex: '女'},
    {name: '李宇春', age: 29, chat: 'lyc', sex: '女'},
    {name: '周杰伦', age: 36, chat: 'zjl'},
    {name: '宋小宝', age: 50, chat: 'sxb'},
    {name: '赵薇', age: 60, chat: 'zw', sex: '女'},
]).then((data)=>{
    console.log(data);
}).catch((err)=>{
    console.log(err);
});*/

// 4.2 查
/*personModel.find({}, (err, docs)=>{
    if(!err){
        console.log(docs[0]);
        console.log(typeof docs);
    }
});*/

/*personModel.findOne({name: '周杰伦'}, (err, docs)=>{
    if(!err){
        console.log(docs);
    }
});*/

/*personModel.find({},{name:1, _id:0, chat:1},(err, docs)=>{
    1需要展示 0不需要展示  没写的默认不查找
    if(!err){
        console.log(docs);
    }else {
        console.log(err);
    }
});*/

/*personModel.find({}, "-_id name", {skip: 3, limit: 2},(err, docs)=>{
    //-_id  不显示
    if(!err){
        console.log(docs);
    }else {
        console.log(err);
    }
});*/

// 4.3 修改
/*personModel.updateOne({name: '王菲'}, {$set: {age: 50}}, (err)=>{
    if(!err){
        console.log('修改成功！');
    }else {
        throw err;
    }
});*/

/*
personModel.updateMany({name: '周杰伦'}, {$set: {age: 20, chat: '我要学IT'}}, (err)=>{
    if(!err){
        console.log('修改成功！');
    }else {
        throw err;
    }
});
*/

// 4.4 删除
/*personModel.remove({name: '宋小宝'}, (err)=>{
    if(err) throw err;
    console.log('删除成功！');
});*/

/*personModel.deleteOne({name: '王菲'}, (err)=>{
    if(err) throw err;
    console.log('删除成功！');
});*/

/*
personModel.deleteMany({}, (err)=>{
    if(err) throw err;
    console.log('删除成功！');
});
*/

personModel.countDocuments({}, (err, count)=>{
    console.log(count);  //统计文档的个数
});

 get set的方法 与之前的方法相似（但是对查询出来的数据进行操作）

const mongoose = require('mongoose');
mongoose.connect('mongodb://localhost:27017/m_data', {useNewUrlParser: true});
mongoose.connection.on('open', ()=>{
    console.log('数据库连接成功！');
});

// 2. 创建模式对象
let Schema = mongoose.Schema;
let personSchema = new Schema({
    name: String,
    age: Number,
    chat: String,
    sex: {
        type: String,
        default: '男'
    }
});

// 3. 创建Model集合对象
let personModel = mongoose.model('person', personSchema);

personModel.findOne({}, (err, docs)=>{
    if(!err){
       /* console.log(docs.get('sex'));
        console.log(docs.set('sex', '男'));*/
        console.log(docs.toJSON());
    }
});