this is a very simple trick on how to select an item in pre binding/pre populated dropdown list from database in asp.net, you can use “FindByValue” method from dropdown list to return you a list item then you can use index of to find the index no of that list item and then set the selected index.

ddlSMSRate.SelectedIndex = ddlSMSRate.Items.IndexOf(ddlSMSRate.Items.FindByValue(drCompany.SMSRate));