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Create a Node.js app that connects to SQL Server and executes queries using Visual Studio Code

These examples may be used with Azure SQL Database

Prerequisites

  1. Node.js installed

Step 1, Setup Node.js for development in Visual Studio Code

  1. Start Visual Studio Code.

  2. Select File > Open Folder (File > Open... on macOS) from the main menu.

  3. In the Open Folder dialog, create a nodeexample folder in a directory of your choice and select it. Then click Select Folder (Open on macOS).

  4. In the Do you trust the authors of the files in this folder? dialog, select Yes, I trust the authors.

  5. Open the Terminal in Visual Studio Code by selecting View > Terminal from the main menu.

    The Terminal opens with the command prompt in the nodeexample folder.

  6. In the Terminal, enter the following command to initialize Node dependencies.

    npm init -y

  7. Next, in the terminal, install tedious and async module in the same project folder by running the following commands:

    npm install tedious
npm install async

Step 2, Create a Node.js app that connects to SQL Server

  1. Create a file in Visual Studio Code by selecting File > New File from the main menu.

  2. Enter connect.js for the file's name in the New File dialog and press enter/return.

  3. Choose the nodeexample directory and create the file.

  4. Replace the contents of connect.js by copying and pasting the code below into the file. Don't forget to replace

    server: '<your_server.database.windows.net>',userName: '<your_username>',password: '<your_password>',port: <your_database_port>,

    with the values of your database.

    varConnection=require('tedious').Connection;varconfig={server: '<your_server.database.windows.net>',authentication: {type: 'default',options: {userName: '<your_username>',password: '<your_password>'}},options: {database: 'master',port: <your_database_port>,
trustServerCertificate: true,
encrypt: true
}};constconnection=newConnection(config);connection.connect((err)=>{if(err){console.log(err)}else{console.log("Connected");connection.close();}});

  5. Save the file.

  6. Run the application in the terminal with the following command:

     node connect.js

    with the output of the command being:

     Connected

Step 3, Create a sample database, schema, and objects

Use Query Editor sheets in Visual Studio Code to run the following TSQL in the Master and SampleDB Databases.

  1. Run the following TSQL in the Master database.

    DROPDATABASE IF EXISTS [SampleDB]; CREATE DATABASE [SampleDB]
GO

  2. Run the following TSQL in the SampleDB database.

    CREATESCHEMATestSchema;
GO
CREATETABLETestSchema.Employees (
Id INT IDENTITY(1,1) NOT NULLPRIMARY KEY,
Name NVARCHAR(50),
Location NVARCHAR(50)
);
GO
INSERT INTOTestSchema.Employees (Name, Location) VALUES
(N'Jared', N'Australia'),
(N'Nikita', N'India'),
(N'Tom', N'Germany');
GO
SELECT*FROMTestSchema.Employees;
GO

Step 4, Create a sample Node.js app that gets rows from the database

  1. Create a file in Visual Studio Code by selecting File > New File from the main menu.

  2. Enter select.js for the file's name in the New File dialog and press enter/return.

  3. Choose the nodeexample directory and create the file.

  4. Replace the contents of select.js by copying and pasting the code below into the file. Don't forget to replace

    server: '<your_server.database.windows.net>',userName: '<your_username>',password: '<your_password>',port: <your_database_port>,

    with the values of your database.

    varConnection=require('tedious').Connection;varconfig={server: '<your_server.database.windows.net>',authentication: {type: 'default',options: {userName: '<your_username>',password: '<your_password>'}},options: {database: 'SampleDB',port: <your_database_port>,
trustServerCertificate: true,
encrypt: true
}};constconnection=newConnection(config);connection.connect((err)=>{// If no error, then good to proceed. console.log("Connected");executeStatement();});varRequest=require('tedious').Request;varTYPES=require('tedious').TYPES;functionexecuteStatement(){varrequest=newRequest("SELECT * from [TestSchema].[Employees];",function(err){if(err){console.log(err);}});varresult="";request.on('row',function(columns){columns.forEach(function(column){if(column.value===null){console.log('NULL');}else{result+=column.value+" ";}});console.log(result);result="";});request.on('done',function(rowCount,more){console.log(rowCount+' rows returned');});// Close the connection after the final event emitted by the request, after the callback passesrequest.on("requestCompleted",function(rowCount,more){connection.close();});connection.execSql(request);}

  5. Save the file.

  6. Run the application in the terminal with the following command:

     node select.js

    with the output of the command being:

    Connected
1 Jared Australia
2 Nikita India
3 Tom Germany

Step 5, Create a sample Node.js app that interacts with the database

  1. Create a file in Visual Studio Code by selecting File > New File from the main menu.

  2. Enter interact.js for the file's name in the New File dialog and press enter/return.

  3. Choose the nodeexample directory and create the file.

  4. Replace the contents of interact.js by copying and pasting the code below into the file. Don't forget to replace

    server: '<your_server.database.windows.net>',userName: '<your_username>',password: '<your_password>',port: <your_database_port>,

    with the values of your database.

    varConnection=require('tedious').Connection;varRequest=require('tedious').Request;varTYPES=require('tedious').TYPES;varasync=require('async');varconfig={server: '<your_server.database.windows.net>',authentication: {type: 'default',options: {userName: '<your_username>',password: '<your_password>'}},options: {database: 'SampleDB',port: <your_database_port>,
trustServerCertificate: true,
encrypt: true
}};functionStart(callback){console.log('Starting...');callback(null,'Jake','United States');}functionInsert(name,location,callback){console.log("Inserting '"+name+"' into Table...");request=newRequest('INSERT INTO TestSchema.Employees (Name, Location) OUTPUT INSERTED.Id VALUES (@Name, @Location);',function(err,rowCount,rows){if(err){callback(err);}else{console.log(rowCount+' row(s) inserted');callback(null,'Nikita','United States');}});request.addParameter('Name',TYPES.NVarChar,name);request.addParameter('Location',TYPES.NVarChar,location);// Execute SQL statementconnection.execSql(request);}functionUpdate(name,location,callback){console.log("Updating Location to '"+location+"' for '"+name+"'...");// Update the employee record requestedrequest=newRequest('UPDATE TestSchema.Employees SET Location=@Location WHERE Name = @Name;',function(err,rowCount,rows){if(err){callback(err);}else{console.log(rowCount+' row(s) updated');callback(null,'Jared');}});request.addParameter('Name',TYPES.NVarChar,name);request.addParameter('Location',TYPES.NVarChar,location);// Execute SQL statementconnection.execSql(request);}functionDelete(name,callback){console.log("Deleting '"+name+"' from Table...");// Delete the employee record requestedrequest=newRequest('DELETE FROM TestSchema.Employees WHERE Name = @Name;',function(err,rowCount,rows){if(err){callback(err);}else{console.log(rowCount+' row(s) deleted');callback(null);}});request.addParameter('Name',TYPES.NVarChar,name);// Execute SQL statementconnection.execSql(request);}functionRead(callback){console.log('Reading rows from the Table...');// Read all rows from tablerequest=newRequest('SELECT Id, Name, Location FROM TestSchema.Employees;',function(err,rowCount,rows){if(err){callback(err);}else{console.log(rowCount+' row(s) returned');callback(null);}});// Print the rows readvarresult="";request.on('row',function(columns){columns.forEach(function(column){if(column.value===null){console.log('NULL');}else{result+=column.value+" ";}});console.log(result);result="";});// Execute SQL statementconnection.execSql(request);}functionComplete(err,result){if(err){callback(err);}else{console.log("Done!");connection.close();}}// Attempt to connect and execute queries if connection goes throughconstconnection=newConnection(config);connection.connect((err)=>{if(err){console.log(err);}else{console.log('Connected');// Execute all functions in the array seriallyasync.waterfall([Start,Insert,Update,Delete,Read],Complete)}});

  5. Save the file.

  6. Run the application in the terminal with the following command:

     node interact.js

    with the results being:

    Connected
Starting...
Inserting 'Jake' into Table...
1 row(s) inserted
Updating Location to 'United States' for 'Nikita'...
1 row(s) updated
Deleting 'Jared' from Table...
1 row(s) deleted
Reading rows from the Table...
2 Nikita United States
3 Tom Germany
4 Jake United States
3 row(s) returned
Done!

Step 2.2 Create a Node.js app that connects to SQL Server using the popular Sequelize ORM

Create the app directory and initialize Node dependencies.

cd~/
mkdir SqlServerSequelizeSample
cd SqlServerSequelizeSample
npm init -y
#Install tedious and Sequelize module in your project folder
npm install tedious
npm install sequelize

a. Open your favourite text editor and create the file orm.js in the directory SqlServerSequelizeSample. b. Paste the contents below into orm.js c. Update the variable for password to use your own password specified in the first module. d. Save and close orm.js

varSequelize=require('sequelize');varuserName='sa';varpassword='your_password';// update mevarhostName='localhost';varsampleDbName='SampleDB';// Initialize Sequelize to connect to sample DBvarsampleDb=newSequelize(sampleDbName,userName,password,{dialect: 'mssql',host: hostName,port: 1433,// Default portlogging: false,// disable logging; default: console.logdialectOptions: {requestTimeout: 30000// timeout = 30 seconds}});// Define the 'User' modelvarUser=sampleDb.define('user',{firstName: Sequelize.STRING,lastName: Sequelize.STRING});// Define the 'Task' modelvarTask=sampleDb.define('task',{title: Sequelize.STRING,dueDate: Sequelize.DATE,isComplete: Sequelize.BOOLEAN});// Model a 1:Many relationship between User and TaskUser.hasMany(Task);console.log('**Node CRUD sample with Sequelize and MSSQL **');// Tell Sequelize to DROP and CREATE tables and relationships in the databasesampleDb.sync({force: true}).then(function(){console.log('\nCreated database schema from model.');// Create demo: Create a User instance and save it to the databaseUser.create({firstName: 'Anna',lastName: 'Shrestinian'}).then(function(user){console.log('\nCreated User:',user.get({plain: true}));// Create demo: Create a Task instance and save it to the databaseTask.create({title: 'Ship Helsinki',dueDate: newDate(2017,04,01),isComplete: false}).then(function(task){console.log('\nCreated Task:',task.get({plain: true}));// Association demo: Assign task to useruser.setTasks([task]).then(function(){console.log('\nAssigned task \''+task.title+'\' to user '+user.firstName+' '+user.lastName);// Read demo: find incomplete tasks assigned to user 'Anna''User.findAll({where: {firstName: 'Anna'},include: [{model: Task,where: {isComplete: false}}]}).then(function(users){console.log('\nIncomplete tasks assigned to Anna:\n',JSON.stringify(users));// Update demo: change the 'dueDate' of a taskTask.findById(1).then(function(task){console.log('\nUpdating task:',task.title+' '+task.dueDate);task.update({dueDate: newDate(2016,06,30)}).then(function(){console.log('dueDate changed:',task.title+' '+task.dueDate);// Delete demo: delete all tasks with a dueDate in 2016console.log('\nDeleting all tasks with with a dueDate in 2016');Task.destroy({where: {dueDate: {$lte: newDate(2016,12,31)}}}).then(function(){Task.findAll().then(function(tasks){console.log('Tasks in database after delete:',JSON.stringify(tasks));console.log('\nAll done!');})})})})})})})})})

Run the orm.js app

 node orm.js
 **Node CRUD sample with Sequelize and MSSQL **
Created database schema from model.
Created User: { id: 1,
firstName: 'Anna',
lastName: 'Shrestinian',
updatedAt: 2016-10-07T03:40:23.000Z,
createdAt: 2016-10-07T03:40:23.000Z }
Created Task: { id: 1,
title: 'Ship Helsinki',
dueDate: 2017-05-01T07:00:00.000Z,
isComplete: false,
updatedAt: 2016-10-07T03:40:23.000Z,
createdAt: 2016-10-07T03:40:23.000Z }
Assigned task 'Ship Helsinki' to user Anna Shrestinian
Incomplete tasks assigned to Anna:
[{"id":1,"firstName":"Anna","lastName":"Shrestinian",
"createdAt":"2016-10-07T03:40:23.000Z",
"updatedAt":"2016-10-07T03:40:23.000Z",
"tasks":[{"id":1,"title":"Ship Helsinki",
"dueDate":"2017-05-01T07:00:00.000Z",
"isComplete":false,
"createdAt":"2016-10-07T03:40:23.000Z",
"updatedAt":"2016-10-07T03:40:23.000Z",
"userId":1}]}]
Updating task: Ship Helsinki Mon May 01 2017 00:00:00 GMT-0700 (PDT)
dueDate changed: Ship Helsinki Sat Jul 30 2016 00:00:00 GMT-0700 (PDT)
Deleting all tasks with with a dueDate in 2016
Tasks in database after delete: []
All done!

Congratulations! You created your first two Node.js apps with SQL Server! Check out the next section to learn about how you can make your Node.js apps faster with SQL Server’s Columnstore feature.