Interface variable in Push notification c# MVC

Question

Hello friends,

 

I am wokring on a push notification function in my MVC project. All push notification is working fine.

 

still I need some help from your side. Please find the code below:-

SqlDependency dependency = new SqlDependency(command);
dependency.OnChange += new OnChangeEventHandler(dependency_OnChange);
if (connection.State == ConnectionState.Closed)
connection.Open();
SqlDataReader reader = command.ExecuteReader();
var listCus = reader.Cast<IDataRecord>()
.Select(x => new
{
Id = (string)x["VEHICLENUMBER"],
CusId = (string)x["CUSTOMERNAME"],
CusName = (string)x["PHONE_NUMBER"],
}).ToList();

you can see the variables highilighted in yellow color. I need to know that where this variables come from. I actually got this code from a web link.

 

I cannot naivigate to its declaration part. defined class. So kindly help me