Question

I am new to the entity framework, and C# but not SQL. I have table [Contact] with multiple fields referencing a lookup table called [XRef_Codes]. First, I want to bind all dropdownlists on an asp.net webform to the filtered lookup table on page load. Second, I want to be able to expose the lookup values (integers and text value) in the contact entity model (see below)

Here is a sample of fields in the
[Contact] table:
FirstName (vchar(50)
LastName (vchar(50)
xPrefix (int)
xSuffix (int)
xReferral (int)
xStatus (int)
xGender (int)
xMaritalStatus (int)
xAgeGroup (int)

I have a self-referencing lookup table called [xRef_Codes] that has the pick values for all the fields prefixed “x” in the contact table (i.e. xPrefix, xSuffix):
[xRef_Codes]
CodeID (int)
CodeName (vchar50)
OfCodeID (int)
SortOrder (int)
SetAsDefault (bit)

[1] In my asp.net form, I want to populate a sorted/filtered dropdownlists FROM xRef_Codes table WHERE OfCodeID=## ORDER BY SetAsDefault, SortOrder. In the page load, I would bind all of the dropdownlists at one time.

[2] I want to associate the related XRef_Codes “CodeName” value as part of the contact object/entity. So I could see that contact.prefix.CodeName =”Mr.” and contact.suffix.CodeName = “Sr.” and contact.gender.CodeName =”Male”, etc.

What is the best approach to this? Can some help me understand if I need to correlate all these fields in the entity framework designer?

Answer 1

I am new to things, so I thought I would share the fruits of my journey. My solution was to utilize the global.asax file, and the Session_Start() object.

First, I created a class for my dropdown list codes called xRefCodesRepository. In my first routine I load the values into a session variable like this:

 public void xref_LoadIntoSessionCache()
         {
             MyDatabaseEntities ctb = new MyDatabaseEntities();
             List<XRef_Codes> allCodes = (from x in ctb.XRef_Codes
                        orderby x.OfCodeID, x.SetAsDefault descending, x.SortOrder
                        where (x.IsImplemented == true)
                        select x).ToList();
             HttpContext.Current.Session["ListOfCodes"] = allCodes;
         }

Second, I add a class routine to fetch my codes by a parentID value. In my case, I have a self-referencing table with fields like CodeID, CodeName, OfCodeID, etc. I fetch my codes like this:

public List<XRef_Codes> xref_GetChildCodes(Int32 OfCodeId)
        {
            //List<XRef_Codes> allCodes = (List<XRef_Codes>)Session["ListOfCodes"];
            List<XRef_Codes> xCodes = xref_GetAllCodes();
            xCodes = (from x in xCodes
                      orderby x.OfCodeID, x.SetAsDefault descending, x.SortOrder
                      where x.OfCodeID == OfCodeId
                      select x).ToList();
            return (xCodes);
        }

Next, I edit my global.asax file. I reference my class folder i.e. using MyDatabase.CLASSNAME;
Then I add a routine in my global.asax that calls the class routine that loads the codes into a session variable:

void Session_Start(object sender, EventArgs e)
        {
            // Code that runs when a new session is started
            xRefCodesRepository x = new xRefCodesRepository();            
            x.xref_LoadIntoSessionCache();
        }

Finally, in my code I reference the session cache to populate various objects.