Saturday, 13 August 2016

Connecting to an MS SQL Instance using NodeJS (Fixing ConnectionError: Port for SQLServer not found in ServerName & Failed to connect to localhost:undefined in 15000ms)

After few debates and discussions on new technologies in the market and how to adapt to them, during the weekend I thought of exploring NodeJS and it applications. Since I spent most of my time designing data-centric applications at office, as the first step I thought of connecting to MS SQL Server using NodeJS.
As a newbie to NodeJS, I went through the official documentation and managed to achieve it. However, during the course, I faced many difficulties and by referring to many of the articles, I was managed to resolve all these hurdles.
So I thought of including these problems which I faced and how to overcome them. So it would be a great help to anyone who’s exploring or trying to achieve this more easily.
For this, I will be using SQL Server 2014 on an Instance (.\SQL2K14).

1. First you need to download and install NodeJS. (https://nodejs.org/en/)
2. Install MSSQL package for Node, using the following syntax: (Use windows command prompt)
npm install mssql
3. Create a file named ‘connecttosql.js’ and include the following code:

//We require mssql package for this sample
var sqlcon = require('mssql');

function GetSQLData(queryCallback){        //A callback function is taken as an argument. Once the operation is completed we will be calling this
   
    //SQL Configuration
    var config = {
        user:'###'            //SQL User Id. Please provide a valid user
        ,password:'######'    //SQL Password. Please provide a valid password
        ,server:'localhost\\SQL2K14'   
        /*
            Since my SQL is an instance I am using 'localhost\\Instance'.
            If you have SQL installed on the default instance, it should be server:'localhost'
        */
        ,database: 'master'        //You can use any database here
    }

    var connection = new sqlcon.Connection(config,function(err){
        //In case of an error print the error to the console. You can have your customer error handling
        if (err) console.log(err);
       
        //Query Database
        var dbQuery = new sqlcon.Request(connection);
        //Purposely we are delaying the results
        dbQuery.query("WAITFOR DELAY '00:00:05';SELECT * FROM INFORMATION_SCHEMA.TABLES",function(err,resultset){
            //In case of an error print the error to the console. You can have your customer error handling
            if (err) console.log(err);
           
            //Passing the resultset to the callback function
            queryCallback(resultset);
        })
    });
}

function callback (resultset){
    console.dir('Results returned and printed from the call back function');
    console.dir(resultset);
   
    //Exit the application
    console.dir('Exiting the Application');
    process.exit(0);
}

//Calling the function
console.dir('Calling GetSQLData');
GetSQLData(callback);
/*
    Once we call this function even there's a delay to return the results
    you will see the next line printing 'Waiting for callback function to get invoked...'
*/
console.dir('Waiting for callback function to get invoked...');

I have provided the relevant information as comments.
Before running the program please make sure the following configurations on the SQL server is already done:

1. Enable TCP/IP Protocols in SQL Server Configuration Manager for both server and client.

image

Or else when running it will result an error shown below:
{ [ConnectionError: Port for SQL2K14 not found in ServerName;[YourPCName];InstanceName;SQL2K14;IsClustered;No;Version;12.0.2000.8;np;\\[YourPCName]\pipe\M
SSQL$SQL2K14\sql\query;;]
  name: 'ConnectionError',
  message: 'Port for SQL2K14 not found in ServerName;[YourPCName];InstanceName;SQL2K14;IsClustered;No;Version;12.0.2000.8;np;\\\\[YourPCName]\\pipe\\MSSQL
$SQL2K14\\sql\\query;;',
  code: 'EINSTLOOKUP' }
{ [ConnectionError: Connection is closed.]
  name: 'ConnectionError',
  message: 'Connection is closed.',
  code: 'ECONNCLOSED' }

2. In SQL Server Configuration Manager under SQL Server Services make sure that ‘SQL Server Browser’ service is running.

image

Or else when running the script it will result an error shown below:
{ [ConnectionError: Failed to connect to localhost:undefined in 15000ms]
  name: 'ConnectionError',
  message: 'Failed to connect to localhost:undefined in 15000ms',
  code: 'ETIMEOUT' }
{ [ConnectionError: Connection is closed.]
  name: 'ConnectionError',
  message: 'Connection is closed.',
  code: 'ECONNCLOSED' }

if the aforementioned issues are already addressed execute the above file using the following syntax in a Windows Command Window:
node connecttosql.js
You should get a similar result which is shown below:
'Calling GetSQLData'
'Waiting for callback function to get invoked...'
'Results returned and printed from the call back function'
[ { TABLE_CATALOG: 'master',
    TABLE_SCHEMA: 'dbo',
    TABLE_NAME: 'spt_fallback_db',
    TABLE_TYPE: 'BASE TABLE' },
  { TABLE_CATALOG: 'master',
    TABLE_SCHEMA: 'dbo',
    TABLE_NAME: 'spt_fallback_dev',
    TABLE_TYPE: 'BASE TABLE' },
  { TABLE_CATALOG: 'master',
    TABLE_SCHEMA: 'dbo',
    TABLE_NAME: 'spt_fallback_usg',
    TABLE_TYPE: 'BASE TABLE' },
  { TABLE_CATALOG: 'master',
    TABLE_SCHEMA: 'dbo',
    TABLE_NAME: 'spt_values',
    TABLE_TYPE: 'VIEW' },
  { TABLE_CATALOG: 'master',
    TABLE_SCHEMA: 'dbo',
    TABLE_NAME: 'spt_monitor',
    TABLE_TYPE: 'BASE TABLE' },
  { TABLE_CATALOG: 'master',
    TABLE_SCHEMA: 'dbo',
    TABLE_NAME: 'MSreplication_options',
    TABLE_TYPE: 'BASE TABLE' } ]
'Exiting the Application'

I hope this will help anyone who’s using node to connect to SQL and facing the aforementioned issues.

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