nodejs connects to mongodb database to implement addition, deletion, modification and query

Preparation

1. Install mongodb through npm command

2. Install the mongodb database. I will not introduce it in detail here. The installation URL is: https://www.jb51.net/article/82522.htm

CRUD operations

Before this, you should have some understanding of the MongoDB database and some of its add, delete, check and modify commands.

1. Add

 var MOngoClient= require("mongodb").MongoClient;
 var DB_URL = "mongodb://localhost:27017/chm";

 function insertData(db)
 {
   var devices = db.collection('vip');
   var data = {"name":"node","age":22,"addr":"nb","addTime":new Date()};
   devices.insert(data,function(error, result){
     if(error)
     {
       console.log('Error:'+ error);
     }else{

       console.log(result.result.n);
     }
     db.close();
   });
 }

 
 MongoClient.connect(DB_URL, function(error, db){
   console.log('Connection successful!');
   insertData(db);
 });
 

2. Search

 var mOngodb= require('mongodb')
 var MOngoClient= require('mongodb').MongoClient;
 var DB_CONN_STR = 'mongodb://localhost:27017/chm';

 var selectData = function(db, callback) {
  //Connect to table
  var collection = db.collection('vip');
  //Query data
  var whereStr = {"name":'node'};
  collection.find(whereStr,function(error, cursor){
   cursor.each(function(error,doc){
     if(doc){
       //console.log(doc);
       if (doc.addTime) {
         console.log("addTime: "+doc.addTime);
       }
     }
   });

  });

 }

 MongoClient.connect(DB_CONN_STR, function(err, db) {
  console.log("Connection successful!");
  selectData(db, function(result) {
   console.log(result);
   db.close();
  });
 });

 

3.Update

 var MOngoClient= require("mongodb").MongoClient;
 var DB_URL = "mongodb://localhost:27017/chm";

 MongoClient.connect(DB_URL, function(error, db){
   console.log("Connection successful!");
   updateData(db);
 });

 function updateData(db)
 {
   var devices = db.collection('vip');
   var whereData = {"name":"node"}
   var updateDat = {$set: {"age":26}}; //If $set is not used, replace the entire data
   devices.update(whereData, updateDat, function(error, result){
     if (error) {
       console.log('Error:'+ error);
     }else{
       console.log(result);
     }
     db.close();
   });
 }

 

4.Delete

 var MOngoClient= require('mongodb').MongoClient;
 var DB_URL = "mongodb://localhost:27017/chm";

 MongoClient.connect(DB_URL, function(error, db){
   console.log("Connection successful");
   deleteData(db);
 });

 function deleteData(db)
 {
   var devices = db.collection('vip');
   var data = {"name":"node"};
   devices.remove(data, function(error, result){
     if (error) {
       console.log('Error:'+ error);
     }else{
       console.log(result.result.n);
     }
     db.close();
   })
 }

 

Stored Procedure

Create stored procedures in mongodb

All stored procedures are stored in db.system.js, and the stored procedures are called through db.eval(“Stored Procedure ID()”);

Call in code:

 var MOngoClient= require("mongodb").MongoClient;
 var DB_URL = "mongodb://localhost:27017/chm";

 MongoClient.connect(DB_URL, function(error,db){
   console.log("Connection successful!");
   callProcess(db)
 });

 function callProcess(db)
 {
   db.eval("get_vip_count()",function(error, result){
     if (error) {
       console.log(error);
     }else{
       console.log("count:"+result);
     }
     db.close();
   });
 }

 

The above is the entire content of this article. I hope it will be helpful to everyone’s study and I hope you will support me a lot.