Skip to main content

Connecting Nodejs to SQL Server with Knex ORM - Part 1

Normally we connect Nodejs to the databases like SQLite, MongoDB, Postgres etc. In this multiple part post, I am going to show you, how we can connect Nodejs with Microsoft's SQL Server using Knex and run CRUD operations.
1. Installation of required packages
In order to connect Nodejs to SQL Server with Knex, we will need following node packages installation:
i. npm install knex
ii. npm install mssql
Once the packages are installed, we can write the following code to connect:
 //Code to KNEX connection settings.
 var knex = require('knex')({  
  client: 'mssql',  
   connection: {  
    user: 'sa',  
    password: 'pwd',  
    server: 'localhost',  
    database: 'Test'  
   }  
 });  
 //Code to query the Table DEPT
 knex.select("*").from("dept")  
 .then(function (depts){  
   depts.forEach((dept)=>{ //use of Arrow Function  
     console.log({...dept});  
   });  
 }).catch(function(err) {  
 // All the error can be checked in this piece of code  
   console.log(err);  
 }).finally(function() {  
   // To close the connection pool  
   knex.destroy();  
 });  
The above example has two parts. Part one does the connection string settings for Knex to connect to SQL Server. Part two actually runs a Select query to select all the rows from table named "Dept". Once the program runs successfully, the output will be, based on table data.
{ DEPTNO: 10, DNAME: 'ACCOUNTING', LOC: 'NEW YORK' }
{ DEPTNO: 20, DNAME: 'RESEARCH', LOC: 'DALLAS' }
{ DEPTNO: 30, DNAME: 'SALES', LOC: 'CHICAGO' }
{ DEPTNO: 40, DNAME: 'OPERATIONS', LOC: 'BOSTON' }
The select query was able to fetch all 4 records from the table named "Dept" in my SQL Server database. The result will vary based on your data and table.
Happy Coding!. | dhandrohit@gmail.com





Comments

Popular posts from this blog

How to use QueryExtenderControl in ASP.NET with LINQ

Queryextender control is a control that helps in doing actions like filtration, searching, sorting etc. on the LINQ Data source with few steps. In fact we don’t have to write any code with this. Screenshot given below is just an example that can easily be achieved through this control. In the above screenshot, we can see that there is a GridView Control that has been binded to a LINQData Source Control. And we have a DropDownlistBox that is also binded to another LINQData Source Control and displaying only grouped jobs. The GridView display all the employees who are matching the Job Parameter. This is done through QueryExtender Control. Also we can search for any name in the employee name's through Query Extender control. The code in the HTML goes like: < form id ="form1" runat ="server">     < div >         Select Job: < asp : DropDownList ID ="Job" runat ="server" DataSourceID ="LinqDataSource2...

SQLServer Error: 15404, Could not obtain information about Windows NT group/user Error code 0x5. [SQLSTATE 42000] (ConnIsLoginSysAdmin)

If we encounter this error "SQLServer Error: 15404, Could not obtain information about Windows NT group/user Error code 0x5. [SQLSTATE 42000] (ConnIsLoginSysAdmin)" in SQL Server in which the job fails because of the user account related problem, then we need to take the following steps to make it work: a. Go to SQL Server Agent. b. Then select the job which is giving error and not running successfully. c. Then choose properties and in the General Tab, change the owner to "SA" or any account that has the administrative privileges. The problem will be resolved.

How to Delete Record through Knex.

This post is all about of deleting records through KNEX ORM in Nodejs. The following code shows how to achieve this: knex("depts").where("deptno","50").del() .then(function (count) {     console.log(count); }) .finally(function () {     knex.destroy(); }); The above code deletes a record from a table "Depts" where Deptno = 50. It has a "then" Promise attached that will show how many records were deleted with this command. Also "finally" is the method that will always execute and will close the KNEX connection. Happy Coding !!!