How To Access Entity Child Object Values

Question

Hi,

I am having some trouble retrieving the value of an enitity child object. I have a parent/child relationship as such:

 Here is the linq statement that gets the addresses for a particular contact:

 Public Function GetAddresses(ByVal contactId As Integer) As List(Of Addresses)
        Using TalentContext = New TalentManagerDBEntities
            Dim Addr = From a In TalentContext.Addresses _
                       From ca In TalentContext.ContactAddresses _
                       Where a.AddressId = ca.Addresses.AddressId And ca.Contacts.ContactId = contactId _
                       Select a
            'Return TalentContext.Addresses.ToList
            Return Addr.ToList
        End Using
    End Function

Public Function GetCountries() As List(Of ConfigCountries)
        Using TalentContext = New TalentManagerDBEntities
            Return TalentContext.ConfigCountries.ToList
        End Using
    End Function

In the code behind of my windows form, i have the following code to set the value of the stateId and countryId for each address:

Dim addresses() As Addresses = wcf.GetAddresses(1)

Dim countryid as Integer =  addresses(i).ConfigCountries.CountryId

The error occurs on the last code, "Object reference not set to an instance of an object". 

My question is how do get he CountryId of address(i)? When I expand the results in debug mode i'm able to see the values in the result of address(1).ConfigCountries.

Thanks.

Answer 1

what is i? are you looping, try 0(zero) if you are only expecting one record.
 if not construct a loop.

Answer 2

I am looping and i is 0 (zero) at this time. Thanks.

Answer 3

On 2/23/2012 9:31 AM, askarii wrote:

> I am looping and i is 0 (zero) at this time. Thanks.

 

You do know that you would have to use an "Include" statement on the

query with the parent/child relationship to get the children objects for

a parent.

 

Or you would have had to do a Load of the child of a parent as you

looped over the parent collection to address the child object.