Use the correct posture nodejs operation of mongodb

mongodb is a type of document databases, which store and query data basically json format, mongodb and nodejs like eggs and tofu natural fit.

Before using nodejs operating mongodb need to understand the hierarchy of mongodb:

• system (mongodb will install some database)
  • admin
• userdefind (user-defined database)
  • database (database name)
    • Collections (set of tables)
      • collection (the collection)
    • functions
    • users

mongodb for nodejs provided official drivers mongdb npm tool can be used directly loaded. Since the model nodejs characteristics, so using mongodb all related operations or by way of a callback promise manner.

Built environment

• Installation nodejs
• nPM heat
• package.json add dependencies

Get all of the database

api:admin.listDatabases

//回调版
const mongoclient = require("mongodb").MongoClient;
const url = "";
mongoclient.connect(url, function (err, client) {
    client.db("").admin().listDatabases(function (err, resp) {
        resp.databases.forEach(function (value, index, arr) {
            console.log(value.name);
        })
    })
});

//promise版

const mongoclient = require("mongodb").MongoClient;
const url = "";
mongoclient.connect(url, function (err, client) {
    client.db("").admin().listDatabases().then(function (data) {
        data.databases.forEach(function (value, index, arr) {
            console.log(value.name);
        })
    }, function (err) {
        console.log(err.message);
    })
});

Create a database

mongodb when the database does not exist, it will automatically create the database, therefore, you can not deliberately created to operate the database

Create Collection

const mongoclient = require("mongodb").MongoClient;
const url = "";
mongoclient.connect(url, function (err, client) {
    client.db("example").createCollection("table1").then(function (result) {
    }, function (err) {
        console.log(err.message);
    })
});

Get all collections

const mongoclient = require("mongodb").MongoClient;
const url = "";
mongoclient.connect(url, function (err, client) {
    client.db("example").listCollections().toArray().then(function (tables) {
        tables.forEach(function (value, index, ts) {
            console.log(value.name);
        })
    }, function (err) {
        console.log(err.message);
    })
});

Insert data collection

const mongoclient = require("mongodb").MongoClient;
const url = "";
mongoclient.connect(url, function (err, client) {
    client.db("example").collection("table1").insert({ name: "张三丰" }).then(function (result) {
    }, function (err) {
        console.log(err.message);
    })
});

Gets a collection of all the data

const mongoclient = require("mongodb").MongoClient;
const url = "";
mongoclient.connect(url, function (err, client) {
    client.db("example").collection("table1").find({}).toArray().then(function (result) {
        result.forEach(function (value, index, arr) {
            console.log(value.name);
        });
    }, function (err) {
        console.log(err.message);
    })
});

change the data

const mongoclient = require("mongodb").MongoClient;
const url = "";
mongoclient.connect(url, function (err, client) {
    client.db("example").collection("table1").update({ name: "李斯" }, { age: 100,name: "李斯" }).then(function (result) {
        console.log(result.result);
    }, function (err) {
        console.log(err.message);
    })
});

Query by the conditions

const mongoclient = require("mongodb").MongoClient;
const url = "";
mongoclient.connect(url, function (err, client) {
    client.db("example").collection("table1").find({ age: 100 }).toArray().then(function (result) {
        result.forEach(function (value, index, arr) {
            console.log(value);
        })
    }, function (err) {
        console.log(err.message);
    })
});

delete data

const mongoclient = require("mongodb").MongoClient;
const url = "";
mongoclient.connect(url, function (err, client) {
    client.db("example").collection("table1").deleteMany({ age: 100 }).then(function (result) {
        console.log(result.result);
    }, function (err) {
        console.log(err.message);
    })
});

A simple mongodb data replication project https://github.com/golangaccount/mongodb_simple_clone