Connection String From Web.config in Class file (Three Tire Architecture)

Here I will explain How to retrieve Connection String from Web.config in Class.cs file when using Three Tire Architecture or More Tires. Here in 3 tire...

• UI Validation (ASP.Net)            //ASP.Net web application
• BLL (Business Logic Layer)     //Windows - Class Library project
• DAL (Data Access Layer)         //Windows - Class Library project

 Here we had TWO ways to get connection string from we.config file.

• In 1st method we can get connection string in web.config file from

  <connectionStrings/> tag i.e.,

  <connectionStrings> 

  <add name="constring"

       connectionString="server=(local)\SQLEXPRESS; 

       database=sampleDB; 

       user id=sa; 

       pwd=*********;" />

   </connectionStrings> 

  and now we need to add reference

  System.Configuration.dll

  and the connection string can be written as shown below

  private string constring = 

         ConfigurationManager.ConnectionStrings["constring"].ToString();

• In 2nd method write the connection string as shown below<configuration> 
  <appSettings>
  <add key="constring" 
  
  value="server=(local)\SQLEXPRESS;
  database=sampleDB;
  user id=sa;
  pwd=*********;"/>    
  </appSettings>
  </configuration> 
  
  and Now in the DataAccessLayer i.e, in the class file write as shown below.
  Before that you need to add  
  
  using System.Configuration;
  
  and now
  
  
  private string constring = 
          ConfigurationSettings.AppSettings["constring"].ToString();
   

For ThreeTite architecture Click HERE