How to solve copy table in entity?

DB1  -  Table Name:STUDENT1

ID   NAME    BRANCHCODE COUNTRYCODE
21   Emily      02          001
26   Alex       56          002
35   Toms       89          003
48   Kelvin     47          004

DB2  -  Table Name:STUDENT2

ID   NAME       BRANCHCODE COUNTRYCODE
14   Mary          32          015
72   Michael       65          066

DB1 -  Table Name: NEWSTD

ID   NAME       BRANCHCODE COUNTRYCODE   Status
14   Mary          32          015          0
72   Michael       65          066          0

public static void Tables()
{
    var studentone=Context.Entities.Student1.Select(p=>new { p.BRANCHCODE,p.COUNTRYCODE});
    //change db code dont write.
    var studenttwo=Context.Entities.Student2.Select(p=>new { p.BRANCHCODE,p.COUNTRYCODE});
    var result=studentone.Intersect(studenttwo);

List<NEWSTD> main=new List<NEWSTD>();
foreach(var item in result)
{
  var item2=student2.SingleOrDefault(s=>s.BRANCHCODE==item.BRANCHCODE && s.COUNTRYCODE==item.COUNTRYCODE);
  if(item2 !=null)
{
     NEWSTD st=new NEWSTD
{
      BRANCHCODE=item2.BRANCHCODE,
      COUNTRYCODE=item2.COUNTRYCOD
};
mainbuild.Add(st);
}
}
DbContext.Entities.NEWSTD.AddRange(main);
DbContext.Entities.SaveChanges();
}