Question

Is there any way to change a connection string programatically? I mean user can pick which site he wants to use using a combobox, and load users on that particular site?

code for config as follows

<add key ="sampleconnectionstring" value="Server=sampleserver;Database=sampledb;User ID=sampleid;Password=samplepassword;Trusted_Connection=False;Encrypt=True;"/>
<add key ="sampleconnectionstring1" value="Server=sampleserver1;Database=sampledb1;User ID=sampleid1;Password=samplepassword;Trusted_Connection=False;Encrypt=True;"/>
<add key ="sampleconnectionstring2" value="Server=sampleserver2;Database=sampledb2;User ID=sampleid2;Password=;Trusted_Connection=False;Encrypt=True;"/>
<add key ="sampleconnectionstring3" value="Server=sampleserver3;Database=sampledb3;User ID=sampleid3;Password=samplepasswrd;Trusted_Connection=False;Encrypt=True;"/>

is there a programmatical(if that’s a word) way of changing between this connection strings depending on the selected item in the combo box? Any help would be appreciated. Thanks.

Answer 1

Depending on what you are using for the database you can load any connection string you want when loading.

For entity framework for example

Entities model = new Entities(connectionString);

For ADO.NET

  using (SqlConnection connection =
        new SqlConnection(connectionString))
    {

    }

For Linq To SQL

Use:

MyDataClassesDataContext db = new MyDataClassesDataContext(dynamicConnString);

For a LinqDataSource, intercept the ContextCreating event and create the DataContext manually as above:

protected void LinqDataSource_ContextCreating(object sender, LinqDataSourceContextEventArgs e)
{
    e.ObjectInstance = new MyDataClassesDataContext (dynamicConnString);
}

(Linq to SQL example taken from: Linq to Sql – Set connection string dynamically based on environment variable