In this article I will explain with an example, how to set and read SQL Server Connection String for Windows Authentication in Web.Config file in ASP.Net using C# and VB.Net.
In ASP.Net Web Applications, one has to reference the System.Configuration Assembly in order to read the SQL Server Connection String for Windows Authentication from the ConnectionStrings section of the Web.Config file.
SQL Server Connection String for Windows Authentication in Web.Config file
SQL Server Connection String for Windows Authentication in Web.Config file is defined as follows and it consists of the following properties.
Data Source - The name of the SQL Server and its Instance.
Initial Catalog - The name of the Database.
Integrated Security - By default False. If set true it signifies that Windows Authentication needs to be used.
<configuration>
<connectionStrings>
<add name="ConString" connectionString="Data Source=Mudassar-PC\SQL2005;Initial Catalog=Northwind;Integrated Security=true" />
</connectionStrings>
</configuration>
Adding System.Configuration reference
In order to access the SQL Server Connection String for Windows Authentication from Web.Config file in code behind, the very first thing you need to do is to add reference of the System.Configuration Assembly to the project in the following way.
1. Right click on the project and click Add Reference option from the Context Menu.
![SQL Server Connection String for Windows Authentication in Web.Config file in ASP.Net]()
2. From the Add Reference dialog box, click on .Net Tab and look for System.Configuration assembly. Once you find it simply select and click OK.
![SQL Server Connection String for Windows Authentication in Web.Config file in ASP.Net]()
3. Once the reference is added, it will be shown in the References folder of the Solution Explorer.
![SQL Server Connection String for Windows Authentication in Web.Config file in ASP.Net]()
Namespaces
You will need to import the following namespace.
C#
using System.Configuration;
VB.Net
Imports System.Configuration
Reading ConnectionString from Web.Config file in ASP.Net using C# and VB.Net
Once the reference is added, you can read the SQL Server Connection String for Windows Authentication from the Web.Config file in the following way.
C#
string connectionString = ConfigurationManager.ConnectionStrings["ConString"].ConnectionString;
VB.Net
Dim connectionString As String = ConfigurationManager.ConnectionStrings("ConString").ConnectionString
