Sugestion on a better way to code this EF update?

Question

I have a block of code that pulls the current menu position and compares it to what users selected, if the selection is different the database is updated with the new selection. As I am still new with EF I was hoping for a general code review for suggestions on a possible better, more efficient, and/or easier way to code this. Here is my existing code:

using (var db = new SectionInfoAdmin())
{
    var dtCategories = (from n in db.Navigation
    where n.SectionID == SectionID
    select new
    {
       n.Category
    }).ToList();

 string PrimaryCategory = dtCategories[0].Category.ToString();

 if (ddlPrimaryCategory.SelectedValue != PrimaryCategory)
 {
    var Category = (from n in db.Navigation
    where n.Category == PrimaryCategory && n.SectionID == SectionID
       select n).First();

    Category.Category = PrimaryCategory;
 }

 if (dtCategories.Count > 1)
 {
    string SecondaryCategory = dtCategories[1].Category.ToString();
    if (ddlSecondaryCategory.SelectedValue == SecondaryCategory)
    {
       var Category = (from n in db.Navigation
       where n.Category == SecondaryCategory && n.SectionID == SectionID
          select n).First();
       Category.Category = SecondaryCategory;
    }
 }
 db.SaveChanges();
 lblResults.Text = "Information updated.";
}

Answer 1

As @dreza mentioned, you might want to move the code around your LINQ-Statements to a method.

public void changeCategoryTo(String newCategory){
   var record = (from n in db.Navigation where n.Category == newCategory
                   && n.SectionId == SectionID select n).First();
   record.Category = newCategory;
}

this greatly reduces duplication.

further points:

1. Try to stick to either camelCase or MixedCase to have consistent and speaking variable names:

   • something like var Category, String PrimaryCategory and similar are diffifult to associate to clear roles in your code.
   • try to refrain from naming your variables after their type only, this leads to greatly increased effort when handling multiple objects of the same type.

2. Your if-statement for updating the SecondaryCategory is different from the if-statement for updating PrimaryCategory