Question

Somethings like :

if(Request["connectionToUse"] + "" == "constr1")
    // use a connection string 1
else 
    // use a connection string 2

is it possible on .NET?

Answer 1

EDIT: This is probably a very bad idea, as said by Oded, but if you really want to then :

modify the webconfig based on the request parameter look at the following example:

string strDevConnection = @"Data Source=DEVELOPMENT\SQLEXPRESS;Initial Catalog=sqlDB;Persist Security Info=True;User ID= ;Password= ";

string strLiveConnection = @"Data Source=PRODUCTION\SQLEXPRESS;Initial Catalog=sqlDB;User id= ;password= ";

Configuration myWebConfig = System.Web.Configuration.WebConfigurationManager.OpenWebConfiguration("~");
if (Request["connectionToUse"] + "" == "constr1")

{

myWebConfig.ConnectionStrings.ConnectionStrings["constr1"].ConnectionString = strDevConnection; //constr1 is the name of the current connectionstring in the web.config

}

else

{

myWebConfig.ConnectionStrings.ConnectionStrings["constr2"].ConnectionString = strLiveConnection;

}
 myWebConfig.Save(); //Save the changes to web config