Node Connection MongoDB

node. js Connection MongoDB

Some introduction

MongoDB Https://www.npmjs.com/package/mongodb
GitHub Project Address Https://github.com/mongodb/node-mongodb-native
Owned by the official MongoDB driver
Document http://mongodb.github.io/node-mongodb-native/3.1/api/
Project Home http://mongodb.github.io/node-mongodb-native/
belongs to a wheel that has been built

Installing MongoDB

PS C:\Users\mingm\Desktop\node> npm install mongodb --save
npm WARN saveError ENOENT: no such file or directory, open ‘C:\Users\mingm\Desktop\node\package.json‘
npm notice created a lockfile as package-lock.json. You should commit this file.
npm WARN enoent ENOENT: no such file or directory, open ‘C:\Users\mingm\Desktop\node\package.json‘
npm WARN node No description
npm WARN node No repository field.
npm WARN node No README data
npm WARN node No license field.

+ [email protected]
added 7 packages from 5 contributors and audited 7 packages in 108.492s
found 0 vulnerabilities

PS C:\Users\mingm\Desktop\node>

Create a database

Well, because of the various versions, the new parser needs to be used. So you need to set the options parameters
That

useNewUrlParser: true

2.0 of drivers
Older versions are not required.

PS C: \ Users \ mingm \ Desktop \ node> node test.js
Database connection establishment
PS C: \ Users \ mingm \ Desktop \ node>

var MongoClient = require (‘mongodb’). MongoClient;
var url = "mongodb: //127.0.0.1: 27017 / mingming"; // URL of the connection

MongoClient.connect (url, {useNewUrlParser: true}, (err, db) => {// call the encapsulated connect to establish a connection with MongoDB according to the url
     if (err) {
         throw err;
     }
     console.log ("Database connection established");
     db.close ();
})

A mingming database was created after the connection

> show dbs;
admin   0.000GB
config  0.000GB
local   0.000GB
> use local;
switched to db local
>

Queried, not yet, because no data was added to it

Create a Collection

That is, create a table

var MongoClient = require (‘mongodb’). MongoClient;
var url = "mongodb: //127.0.0.1: 27017 / mingming"; // URL of the connection

MongoClient.connect (url, {useNewUrlParser: true}, (err, db) => {// call the encapsulated connect to establish a connection with MongoDB according to the url
     if (err) {
         throw err;
     }
     console.log ("Database connection established");
     var dbase = db.db (‘mingming’); // select database as mingming
     dbase.createCollection (‘site’, (err, res) => {// Create database as site collection under mingming
         if (err) {
             throw err;
         }
         console.log (‘Create collection!’);
         db.close ();
     });
});
PS C: \ Users \ mingm \ Desktop \ node> node test.js
Database connection establishment
Create a collection!
PS C: \ Users \ mingm \ Desktop \ node>

Check out this watch.

> show dbs;
admin     0.000GB
config    0.000GB
local     0.000GB
mingming  0.000GB
> use mingming
switched to db mingming
> show ceoolection;
2018-07-31T23:12:55.014+0800 E QUERY    [js] Error: don‘t know how to show [ceoolection] :
[email protected]/mongo/shell/utils.js:1043:11
[email protected]/mongo/shell/utils.js:755:15
@(shellhelp2):1:1
> show collections;
site
> db.site.find();
>

Curd inserting data

PS C: \ Users \ mingm \ Desktop \ node> node test.js
Document inserted successfully!
PS C: \ Users \ mingm \ Desktop \ node>
var MongoClient = require (‘mongodb’). MongoClient;
var url = "mongodb: //127.0.0.1: 27017 / mingming"; // URL of the connection

MongoClient.connect (url, {useNewUrlParser: true}, (err, db) => {// call the encapsulated connect to establish a connection with MongoDB according to the url
     if (err) {
         throw err;
     }
     var dbo = db.db (‘mingming’);
     var myobj = {name: "mingming", url: "www.iming.info"};
     dbo.collection (‘site’). insertOne (myobj, (err, res) => {// mongodb syntax mingming.site.insert (myObj);
         if (err) {
             throw err;
         }
         console.log ("Document inserted successfully!");
         db.close ();
     });
});
> db.site.find ();
{"_id": ObjectId ("5b607e4d5b8ced1c5cb8a7e4"), "name": "mingming", "url": "www.iming.info"}
{"_id": ObjectId ("5b607e6ee7b6e82d604d5a4d"), "name": "mingming", "url": "www.iming.info"}
>

Inserting more than one data

> db.site.find (). pretty ();
{
        "_id": ObjectId ("5b607e4d5b8ced1c5cb8a7e4"),
        "name": "mingming",
        "url": "www.iming.info"
}
{
        "_id": ObjectId ("5b607e6ee7b6e82d604d5a4d"),
        "name": "mingming",
        "url": "www.iming.info"
}
{
        "_id": ObjectId ("5b6080037aa38239e46c0dc1"),
        "name": "mingming",
        "url": "www.iming.info",
        "type": "cn"
}
{
        "_id": ObjectId ("5b6080037aa38239e46c0dc2"),
        "name": "google",
        "url": "www.google.com.hk",
        "type": "un"
}
{
        "_id": ObjectId ("5b6080037aa38239e46c0dc3"),
        "name": "twitter",
        "url": "www.twitter.com",
        "type": "un"
}
>
var MongoClient = require (‘mongodb’). MongoClient;
var url = "mongodb: //127.0.0.1: 27017 / mingming"; // URL of the connection

MongoClient.connect (url, {useNewUrlParser: true}, (err, db) => {// call the encapsulated connect to establish a connection with MongoDB according to the url
    if (err) {
        throw err;
    }
    var dbo = db.db (‘mingming’);
    var myobj = [
        {name: "mingming", url: "www.iming.info", type: "cn"},
        {name: "google", url: "www.google.com.hk", type: "un"},
        {name: "twitter", url: "www.twitter.com", type: "un"},
    ];
    dbo.collection (‘site’). insertMany (myobj, (err, res) => {// mongodb syntax mingming.site.insert (myObj);
        if (err) {
            throw err;
        }
        console.log ("Document inserted successfully!");
        db.close ();
    });
});
PS C: \ Users \ mingm \ Desktop \ node> node test.js
Document inserted successfully!
PS C: \ Users \ mingm \ Desktop \ node>

Querying data

 PS c:\users\mingm\desktop\node> node test.js[{_id:5b607e4d5b8ced1c5cb8a7e4, Name: ' mingming ', url: ' Www.iming.info '}, {_id:5b607e6ee7b6e82d604d5a4d, Name: ' mingming ', url: ' Www.iming.info '}, {_ID:5B6080037AA 38239E46C0DC1, Name: ' mingming ', url: ' Www.iming.info ', type: ' CN '}, {_ID:5B6080037AA38239E46C0DC2, Name: ' Google ', url: ' www.google.com.hk ', type: ' un '}, {_ID:5B6080037AA38239E46C0DC3, name: ' Twitter ', url: ' www . twitter.com ', type: ' UN '}]ps c:\users\mingm\desktop\node>PS C: \ Users \ mingm \ Desktop \ node> node test.js
[{_id: 5b607e4d5b8ced1c5cb8a7e4,
    name: ‘mingming’,
    url: ‘www.iming.info’},
  {_id: 5b607e6ee7b6e82d604d5a4d,
    name: ‘mingming’,
    url: ‘www.iming.info’},
  {_id: 5b6080037aa38239e46c0dc1,
    name: ‘mingming’,
    url: ‘www.iming.info’,
    type: ‘cn’},
  {_id: 5b6080037aa38239e46c0dc2,
    name: ‘google’,
    url: ‘www.google.com.hk’,
    type: ‘un’},
  {_id: 5b6080037aa38239e46c0dc3,
    name: ‘twitter’,
    url: ‘www.twitter.com’,
    type: ‘un‘}]
PS C: \ Users \ mingm \ Desktop \ node>
var MongoClient = require (‘mongodb’). MongoClient;
var url = "mongodb: //127.0.0.1: 27017 / mingming"; // URL of the connection

MongoClient.connect (url, {useNewUrlParser: true}, (err, db) => {// call the encapsulated connect to establish a connection with MongoDB according to the url
    if (err) {
        throw err;
    }
    var dbo = db.db (‘mingming’);
    dbo.collection (‘site’). find ({}). toArray ((err, result) => {// After using find () to complete the query, use toArray to callback the completed data
        if (err) {
            throw err;
        }
        console.log (result); // Output the result of the callback (because the result is temporarily stored in memory, make sure there is enough memory to save it, or use a stream)
        db.close ();
    });
}) ;;
> db.site.find (). pretty ();
{
        "_id": ObjectId ("5b607e4d5b8ced1c5cb8a7e4"),
        "name": "mingming",
        "url": "www.iming.info"
}
{
        "_id": ObjectId ("5b607e6ee7b6e82d604d5a4d"),
        "name": "mingming",
        "url": "www.iming.info"
}
{
        "_id": ObjectId ("5b6080037aa38239e46c0dc1"),
        "name": "mingming",
        "url": "www.iming.info",
        "type": "cn"
}
{
        "_id": ObjectId ("5b6080037aa38239e46c0dc2"),
        "name": "google",
        "url": "www.google.com.hk",
        "type": "un"
}
{
        "_id": ObjectId ("5b6080037aa38239e46c0dc3"),
        "name": "twitter",
        "url": "www.twitter.com",
        "type": "un"
}
>

Querying data for a specified condition

 PS c:\users\mingm\desktop\node> node test.js[{_id:5b607e4d5b8ced1c5cb8a7e4, Name: ' mingming ', url: ' Www.iming.info '}, {_id:5b607e6ee7b6e82d604d5a4d, Name: ' mingming ', url: ' Www.iming.info '}, {_ID:5B6080037AA 38239E46C0DC1, Name: ' mingming ', url: ' Www.iming.info ', type: ' CN '}]ps C:\users\mingm\desktop\node>pre>PS C: \ Users \ mingm \ Desktop \ node> node test.js
[{_id: 5b607e4d5b8ced1c5cb8a7e4,
    name: ‘mingming’,
    url: ‘www.iming.info’},
  {_id: 5b607e6ee7b6e82d604d5a4d,
    name: ‘mingming’,
    url: ‘www.iming.info’},
  {_id: 5b6080037aa38239e46c0dc1,
    name: ‘mingming’,
    url: ‘www.iming.info’,
    type: ‘cn’}]
PS C: \ Users \ mingm \ Desktop \ node>
var MongoClient = require (‘mongodb’). MongoClient;
var url = "mongodb: //127.0.0.1: 27017 / mingming"; // URL of the connection

MongoClient.connect (url, {useNewUrlParser: true}, (err, db) => {// call the encapsulated connect to establish a connection with MongoDB according to the url
    if (err) {
        throw err;
    }
    var dbo = db.db (‘mingming’);
    var whereStr = {"name": "mingming"}; // query condition
    dbo.collection (‘site’). find (whereStr) .toArray ((err, result) => {// After using find () to complete the query, use toArray to callback the completed data.
        if (err) {
            throw err;
        }
        console.log (result); // Output the result of the callback (because the result is temporarily stored in memory, make sure there is enough memory to save it, or use a stream)
        db.close ();
    });
}) ;;

Update data

PS C: \ Users \ mingm \ Desktop \ node> node test.js
Document updated successfully
PS C: \ Users \ mingm \ Desktop \ node>
var MongoClient = require (‘mongodb’). MongoClient;
var url = "mongodb: //127.0.0.1: 27017 / mingming"; // URL of the connection

MongoClient.connect (url, {useNewUrlParser: true}, (err, db) => {// call the encapsulated connect to establish a connection with MongoDB according to the url
    if (err) {
        throw err;
    }
    var dbo = db.db (‘mingming’);
    var whereStr = {"name": "mingming"}; // query condition
    var updateStr = {$ set: {"url": "AmingA"}};
    dbo.collection (‘site’). updateOne (whereStr, updateStr, (err, result) => {// After using find () to complete the query, use toArray to callback the completed data.
        if (err) {
            throw err;
        }
        console.log (‘Document updated successfully’); // Output the result of the callback (because the result is temporarily stored in memory, make sure there is enough memory to save it, or use a stream)
        db.close ();
    });
}) ;;
> db.site.find ({"name": "mingming"}). pretty ();
{
        "_id": ObjectId ("5b607e4d5b8ced1c5cb8a7e4"),
        "name": "mingming",
        "url": "AmingA"
}
{
        "_id": ObjectId ("5b607e6ee7b6e82d604d5a4d"),
        "name": "mingming",
        "url": "www.iming.info"
}
{
        "_id": ObjectId ("5b6080037aa38239e46c0dc1"),
        "name": "mingming",
        "url": "www.iming.info",
        "type": "cn"
}
>

Updates for MongoDB

> db.site.update({"name":"mingming"}, {$set: {"url":""}});
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.site.find({"name":"mingming"});
{ "_id" : ObjectId("5b607e4d5b8ced1c5cb8a7e4"), "name" : "mingming", "url" : "" }
{ "_id" : ObjectId("5b607e6ee7b6e82d604d5a4d"), "name" : "mingming", "url" : "www.iming.info" }
{ "_id" : ObjectId("5b6080037aa38239e46c0dc1"), "name" : "mingming", "url" : "www.iming.info", "type" : "cn" }
>

Update more than one data

PS C: \ Users \ mingm \ Desktop \ node> node test.js
{n: 3, nModified: 3, ok: 1}
PS C: \ Users \ mingm \ Desktop \ node>
var MongoClient = require (‘mongodb’). MongoClient;
var url = "mongodb: //127.0.0.1: 27017 / mingming"; // URL of the connection

MongoClient.connect (url, {useNewUrlParser: true}, (err, db) => {// call the encapsulated connect to establish a connection with MongoDB according to the url
    if (err) {
        throw err;
    }
    var dbo = db.db (‘mingming’);
    var whereStr = {"name": "mingming"}; // query condition
    var updateStr = {$ set: {"url": ""}};
    dbo.collection (‘site’). updateMany (whereStr, updateStr, (err, result) => {// After using find () to complete the query, use toArray to callback the completed data.
        if (err) {
            throw err;
        }
        console.log (result.result); // Output the result of the callback (because the result is temporarily stored in memory, make sure there is enough memory to save it, or use a stream)
        db.close ();
    });
}) ;;
> db.site.find ({"name": "mingming"});
{"_id": ObjectId ("5b607e4d5b8ced1c5cb8a7e4"), "name": "mingming", "url": ""}
{"_id": ObjectId ("5b607e6ee7b6e82d604d5a4d"), "name": "mingming", "url": ""}
{"_id": ObjectId ("5b6080037aa38239e46c0dc1"), "name": "mingming", "url": "", "type": "cn"}
> 

Delete data

Likewise Deleteone and Deletemany () are not elaborated

Sort

Use sort () to finish sorting

PS C: \ Users \ mingm \ Desktop \ node> node test.js
[{_id: 5b6080037aa38239e46c0dc2,
    name: ‘google’,
    url: ‘www.google.com.hk’,
    type: ‘un’},
  {_id: 5b6080037aa38239e46c0dc3,
    name: ‘twitter’,
    url: ‘www.twitter.com’,
    type: ‘un’},
  {_id: 5b6080037aa38239e46c0dc1,
    name: ‘mingming’,
    url: ‘‘,
    type: ‘cn’},
  {_id: 5b607e4d5b8ced1c5cb8a7e4, name: ‘mingming’, url: ‘‘},
  {_id: 5b607e6ee7b6e82d604d5a4d, name: ‘mingming’, url: ‘‘}]
PS C: \ Users \ mingm \ Desktop \ node>
var MongoClient = require (‘mongodb’). MongoClient;
var url = "mongodb: //127.0.0.1: 27017 / mingming"; // URL of the connection

MongoClient.connect (url, {useNewUrlParser: true}, (err, db) => {// call the encapsulated connect to establish a connection with MongoDB according to the url
    if (err) {
        throw err;
    }
    var dbo = db.db (‘mingming’);
    var mysort = {type: -1}; // descending
    dbo.collection (‘site‘). find (). sort (mysort) .toArray ((err, result) => {
            if (err) {
            throw err;
        }
        console.log (result); // Output the result of the callback (because the result is temporarily stored in memory, make sure there is enough memory to save it, or use a stream)
        db.close ();
    });
}) ;;

MongoDB syntax

> db.site.find({}).sort({type:-1});
{ "_id" : ObjectId("5b6080037aa38239e46c0dc2"), "name" : "google", "url" : "www.google.com.hk", "type" : "un" }
{ "_id" : ObjectId("5b6080037aa38239e46c0dc3"), "name" : "twitter", "url" : "www.twitter.com", "type" : "un" }
{ "_id" : ObjectId("5b6080037aa38239e46c0dc1"), "name" : "mingming", "url" : "", "type" : "cn" }
{ "_id" : ObjectId("5b607e4d5b8ced1c5cb8a7e4"), "name" : "mingming", "url" : "" }
{ "_id" : ObjectId("5b607e6ee7b6e82d604d5a4d"), "name" : "mingming", "url" : "" }
>

Page out

Using limit, paging and sorting are all channels (a concept from Linux)

PS C:\Users\mingm\Desktop\node> node test.js
[ { _id: 5b607e4d5b8ced1c5cb8a7e4, name: ‘mingming‘, url: ‘‘ },
  { _id: 5b607e6ee7b6e82d604d5a4d, name: ‘mingming‘, url: ‘‘ } ]
PS C:\Users\mingm\Desktop\node>

Skips a specified number of bars

PS C: \ Users \ mingm \ Desktop \ node> node test.js
[{_id: 5b6080037aa38239e46c0dc1,
     name: ‘mingming’,
     url: ‘‘,
     type: ‘cn’},
   {_id: 5b6080037aa38239e46c0dc2,
     name: ‘google’,
     url: ‘www.google.com.hk’,
     type: ‘un‘}]
PS C: \ Users \ mingm \ Desktop \ node>
var MongoClient = require (‘mongodb’). MongoClient;
var url = "mongodb: //127.0.0.1: 27017 / mingming"; // URL of the connection

MongoClient.connect (url, {useNewUrlParser: true}, (err, db) => {// call the encapsulated connect to establish a connection with MongoDB according to the url
     if (err) {
         throw err;
     }
     var dbo = db.db (‘mingming’);
     dbo.collection (‘site‘). find (). skip (2) .limit (2) .toArray ((err, result) => {
             if (err) {
             throw err;
         }
         console.log (result); // Output the result of the callback (because the result is temporarily stored in memory, make sure there is enough memory to save it, or use a stream)
         db.close ();
     });
}) ;;

Random reading of one piece of data

PS C: \ Users \ mingm \ Desktop \ node> node test.js
[{_id: 5b6080037aa38239e46c0dc2,
    name: ‘google’,
    url: ‘www.google.com.hk’,
    type: ‘un‘}]
[{_id: 5b6080037aa38239e46c0dc1,
    name: ‘mingming’,
    url: ‘‘,
    type: ‘cn’}]
[{_id: 5b6080037aa38239e46c0dc2,
    name: ‘google’,
    url: ‘www.google.com.hk’,
    type: ‘un‘}]
[{_id: 5b607e6ee7b6e82d604d5a4d, name: ‘mingming’, url: ‘‘}]
[{_id: 5b607e4d5b8ced1c5cb8a7e4, name: ‘mingming’, url: ‘‘}]
[{_id: 5b6080037aa38239e46c0dc1,
    name: ‘mingming’,
    url: ‘‘,
    type: ‘cn’}]
[{_id: 5b607e4d5b8ced1c5cb8a7e4, name: ‘mingming’, url: ‘‘}]
[{_id: 5b607e6ee7b6e82d604d5a4d, name: ‘mingming’, url: ‘‘}]
[{_id: 5b607e6ee7b6e82d604d5a4d, name: ‘mingming’, url: ‘‘}]
[{_id: 5b607e4d5b8ced1c5cb8a7e4, name: ‘mingming’, url: ‘‘}]
PS C: \ Users \ mingm \ Desktop \ node> node test.js
[{_id: 5b6080037aa38239e46c0dc2,
    name: ‘google’,
    url: ‘www.google.com.hk’,
    type: ‘un‘}]
[{_id: 5b6080037aa38239e46c0dc1,
    name: ‘mingming’,
    url: ‘‘,
    type: ‘cn’}]
[{_id: 5b6080037aa38239e46c0dc3,
    name: ‘twitter’,
    url: ‘www.twitter.com’,
    type: ‘un‘}]
[{_id: 5b607e6ee7b6e82d604d5a4d, name: ‘mingming’, url: ‘‘}]
[{_id: 5b607e6ee7b6e82d604d5a4d, name: ‘mingming’, url: ‘‘}]
[{_id: 5b6080037aa38239e46c0dc1,
    name: ‘mingming’,
    url: ‘‘,
    type: ‘cn’}]
[{_id: 5b6080037aa38239e46c0dc1,
    name: ‘mingming’,
    url: ‘‘,
    type: ‘cn’}]
[{_id: 5b607e4d5b8ced1c5cb8a7e4, name: ‘mingming’, url: ‘‘}]
[{_id: 5b6080037aa38239e46c0dc3,
    name: ‘twitter’,
    url: ‘www.twitter.com’,
    type: ‘un‘}]
[{_id: 5b6080037aa38239e46c0dc3,
    name: ‘twitter’,
    url: ‘www.twitter.com’,
    type: ‘un‘}]
PS C: \ Users \ mingm \ Desktop \ node>
var MongoClient = require (‘mongodb’). MongoClient;
var url = "mongodb: //127.0.0.1: 27017 / mingming"; // URL of the connection

MongoClient.connect (url, {useNewUrlParser: true}, (err, db) => {// call the encapsulated connect to establish a connection with MongoDB according to the url
    if (err) {
        throw err;
    }
    var dbo = db.db (‘mingming’);
    for (var i = 0; i <10; i ++) {
        dbo.collection (‘site‘). aggregate ([{$ sample: {size: 1}}]). toArray ((err, result) => {
                if (err) {
                throw err;
            }
            console.log (result); // Output the result of the callback (because the result is temporarily stored in memory, make sure there is enough memory to save it, or use a stream)
        });
    };
    db.close ();
}) ;; 

The same pipes are used

Blog

Www.iming.info

Node Connection MongoDB