how to use class file for multiple connection in C#?

Question

http://www.c-sharpcorner.com/forums/asp-net-how-to-use-class-file-for-connection-in-c-sharp

in this link only singale connection string is in use but i need to declare multiple connection string in class file and use in hole application.

originally its like one application with multiple database. all database having same schema.user select the database name from dropdown then on dropdown selection the user must be redirect to its selected database. means i have to manage multiple connections of database on dropdown selection

my application requires to select the connection string on dropdown selection.

Ashiwani Sharma · Answer

Hi Chetan Use constructor overloading for multiple connection

Chetan Sarode · Answer

please give one example..Thanks in advance

Francis · Answer

The simple solution is you can use Session object. Just store the selected connection string on a session variable and pass the same to the class file.

Chetan Sarode · Answer

now i am trying another way- managing connection string on dropdown selection now the question is this connection object is not working in another webform because i need to use this connection on hole app using this connection object how to solve Code:- String connection = String . Empty ; protected void DropDownList1_SelectedIndexChanged ( object sender  EventArgs e ) { if ( DropDownList1 . SelectedItem . Text . Equals ( RVL LOGISTICS (I) PVT LTD )) { connection = ConfigurationManager . ConnectionStrings [ CompMasterConnectionString ]. ConnectionString ; } else if ( DropDownList1 . SelectedItem . Text . Equals ( SIMONS SHIPPING PVT LTD )) { connection = ConfigurationManager . ConnectionStrings [ DUM01ConnectionString ]. ConnectionString ; } else { DropDownList2 . Enabled = false ; } }

Francis · Answer

As you told the class file contains a logic to manage with single connection string. Sodon't change anything in that class file. Instead of that you could try to pass the connection string alone to the class file from your dropdown selection. So basedon the connection stringtheclass file will work as you expected.It is themost appropriate way toachieve yourgoal. Let me know your concern if any.

Chetan Sarode · Answer

but how to manage with dropdownlist and how to access in other webform

Midhun T P · Answer

Hi Try this. You can pass parameter to the method for selecting connection string based on that. using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Configuration; using System.Data.SqlClient; /// /// Summary description for connection /// public class connection { static string my_connection1 =  ; static SqlConnection my_connection = null ; public connection() { // // TODO: Add constructor logic here // } public SqlConnection getconnection( string opt) { if (opt == 1 ) my_connection1 = ConfigurationManager .ConnectionStrings[ connection1 ].ConnectionString; else my_connection1 = ConfigurationManager .ConnectionStrings[ connection2 ].ConnectionString; if (my_connection == null ) { my_connection = new SqlConnection (my_connection1); my_connection.Open(); } return my_connection; } }