How to store a Global SqlConnection

Global Connecton String can be stored in a  web.Config .By Storing this Connection in Web.Cofig you can access this Connection String thorugh out your Application

.

How to Create a Web.Config file?

 1)     First  create one Defalut.asp page

 2)     Next in Menus click on WebSite-àAdd NewItem a window will open.In window select 'Web Cinfiguration File' and give the name to  Web Configuratin File and click Add Button.

When you click on Add Button your created web.config file can see in your Solution Explorer.

How to write a Connection string in Web.Config?

Open your Web.Config file (or) Double click on your web.config file.when it opens , some prewritten  XML tags you can see as follows

<?xml version="1.0"?>
<!-- 
    Note: As an alternative to hand editing this file you can use the 
    web admin tool to configure settings for your application. Use
    the Website->Asp.Net Configuration option in Visual Studio.
    A full list of settings and comments can be found in 
    machine.config.comments usually located in 
    \Windows\Microsoft.Net\Framework\v2.x\Config 
-->
<configuration>
    <appSettings/>
    <connectionStrings/>
    <system.web>
        <!-- 
            Set compilation debug="true" to insert debugging 
            symbols into the compiled page. Because this 
            affects performance, set this value to true only 
            during development.
        -->
        <compilation debug="false" />
        <!--
            The <authentication> section enables configuration 
            of the security authentication mode used by 
            ASP.NET to identify an incoming user. 
        -->
        <authentication mode="Windows" />
        <!--
            The <customErrors> section enables configuration 
            of what to do if/when an unhandled error occurs 
            during the execution of a request. Specifically, 
            it enables developers to configure html error pages 
            to be displayed in place of a error stack trace.
 
        <customErrors mode="RemoteOnly" defaultRedirect="GenericErrorPage.htm">
            <error statusCode="403" redirect="NoAccess.htm" />
            <error statusCode="404" redirect="FileNotFound.htm" />
        </customErrors>
        -->
    </system.web>
</configuration>
 

In the above Code some text is written in green color.It had written in Comments.no need to worry about this.

1) Next we have to write Connection String in between the tags

<configuration>

</configuration>

2) we have to write a <connectionStrings> </connectionStrings> tags in between the <configuration> </configuration>

3) Next we have to use a <add> tag in between the <connectionStrings>  </connectionStrings>

4) in <add> tag we have to use attribute named connectionString and name

5) By using connectionString attribute we have to write our SqlConnection string as follows.

connectionString="Data Source=INTHIYAAZ;Initial Catalog=shakeer;User ID=sa;Password=sa"

6) To call this connection string we are giving name to this connection string by using name attribute.

The complete connection string looks as follows.

 <configuration>
            <connectionStrings>
                        <add name="sqlconnectionstring" connectionString="Data  Source=INTHIYAAZ;Initial Catalog=DB;User ID=sa;Password=sa" />
            </connectionStrings> 
</configuration>
 

Write the above lines in between the < ?xml version="1.0"?> <appSettings/>

In the above lines I given a connection string name as name="sqlconnectionstring",and DB is my Data Base name.

How to call a Connection String in default.aspx.cs page?

The connection can be called by using

ConfigurationManager.ConnectionStrings["name of the connection given in web.cong file"].ConnectionString)

Use the above line with SqlConnection class as follows:

SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["sqlconnectionstring"].ConnectionString);
   conn.Open();
   Response.Write("connection Connected sucessfully");
 

Here "sqlconnectionstring" is the name of the connection string used given in web.config file.

Interview question on web.config:
 
1)what is the use of using web.config file
 
Ans) By using this web.config file we can store sqlconnection string.This SqlConnection String can be acessed any where in your application.for security purpose of connection string also we can use web.config.
 
2) Can we have more than one web.config file in our application?
 
Ans) Yes,we can create or use more than one web.config file in our application.
 
3)How you will write a Connection String in web.Config fiel?
 
Ans) Then write below lines of code:
 
<configuration>
            <connectionStrings>
                        <add name="sqlconnectionstring" connectionString="Data  Source=INTHIYAAZ;Initial Catalog=DB;User ID=sa;Password=sa" />
            </connectionStrings>