Completely master the addition, deletion, modification and query functions of nodejs operating mongodb

This article mainly introduces the addition, deletion, modification and query functions of nodejs operating mongodb. It briefly analyzes the installation of the mongodb module and analyzes the related implementation skills of nodejs operating mongodb database for addition, deletion, modification and query in the form of examples. Friends who need it can refer to it. I hope Can help everyone.

Install related modules

If you use this, you need to install the required modules yourself first and enter

in the root directory

npm install mongodb --save

Install the module. After the installation is successful, you can proceed with the following steps.

Introduction of files

The following is the relevant code I wrote, put it in the relevant directory that you can quote, I put it in the root of express Directory

function Mongo(options) {
  this.settings = {
    url: 'mongodb://localhost:27017/jk',
    MongoClient:require('mongodb').MongoClient,
    assert:require('assert')
  };
  for(let i in options){
    this.settings[i] = options[i];
  }
  this._run = function (fun) {
    let that = this;
    let settings = this.settings;
    this.settings.MongoClient.connect(this.settings.url, function (err, db) {
      settings.assert.equal(null, err);
      console.log("Connected correctly to server");
      fun(db, function () {
        db.close();
      });
    });
  };
  this.insert = function (collectionName, data, func) {
    //增加数据
    let insertDocuments = function (db, callback) {
      let collection = db.collection(collectionName);
      collection.insertMany([
        data
      ], function (err, result) {
        if (!err) {
          func(true);
        } else {
          func(false);
        }
        callback(result);
      });
    };
    this._run(insertDocuments);
  };
  this.update = function (collectionName, updateData, data, func) {
    //更新数据
    let updateDocument = function (db, callback) {
      let collection = db.collection(collectionName);
      collection.updateOne(updateData
        , {$set: data}, function (err, result) {
          if (!err) {
            func(true);
          } else {
            func(false);
          }
          callback(result);
        });
    };
    this._run(updateDocument);
  };
  this.delete = function (collectionName, data, func) {
    //删除数据
    let deleteDocument = function (db, callback) {
      let collection = db.collection(collectionName);
      collection.deleteOne(data, function (err, result) {
        if (!err) {
          func(true);
        } else {
          func(false);
        }
        callback(result);
      });
    };
    this._run(deleteDocument);
  };
  this.find = function (collectionName, data, func) {
    //查找数据
    let findDocuments = function (db, callback) {
      // Get the documents collection
      let collection = db.collection(collectionName);
      // Find some documents
      collection.find(data).toArray(function (err, docs) {
        if (!err) {
          func(true,docs);
        }
        else {
          func(false, err);
        }
        callback(docs);
      });
    };
    this._run(findDocuments);
  };
}
module.exports = Mongo;

I saved it to a file named server.js

Use

We first introduce the module when we need to use the page. For example, I introduce it in the routing file index.js:

##

const Server = require("../server.js");

Then we need to instantiate the object, as follows ：

let server = new Server();

If you need to configure related information, you can pass in an object configuration during instantiation, and you can configure the database address:

let server = new Server({url:"mongodb://localhost:27017/mydb"});

encapsulates four methods, add, delete, modify and check, respectively

Add method

server.insert(数据表名,需要插入的数据（键值对的对象）,回调函数);

Update method

server.update(数据表名,查询的数据（对象）,更新的数据（对象）,回调函数);

Delete method

server.delete(数据表名,查询的数据（对象）,回调函数);

Search method

server.find(数据表名,查询的数据（对象）,回调函数);

The callback function will return two values, the first Boolean type, whether the processing is successful, the second value, the search return The number of found items, and others will return the number of successfully processed items (now only one item is processed at a time)

Use case

For example, I If I need to find data in a route, I need this:

server.find("users",{username:"username"},function (bool,data) {
    if(bool){
      console.log("查询到数据为"+data.length+"条");
    }
    else{
      console.log(data);
    }
  });
});

The above code queries the data of the field where username is username in the users table. If successful, the following data will return an array. If an error occurs, the data error will be returned directly.

Related recommendations:

php database add, delete, modify and query methods

AngularJs add, delete, modify and query methods

Implementation of the basic writing method of adding, deleting, modifying and querying MySql in NodeJS

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