Chapter 14, first 'Try It Out'

alharlow · March 16th, 2011, 12:07 AM

Following along chptr 14 while creating my own object model. Has only one table. I did the 'add new item', selecting 'entity data model' as described in the book. Went through entity dialog and it shows me the object model it created from my one table. I saved the .edmx as instructed. In the app_code folder I see the .edmx file but looking at the app_code folder for your PlanetWrox model, it also created a file called PlanetWrox.Designer.vb. I didn't get one of those in my app_code folder. Also after typing in the code in step 9 for the page_load, when I try to apply the 'not defined' fix shown under the code on page 483 the Ctrl+. doesn't give me the choices shown in figure 14-3. What am I doing wrong?

Imar · March 16th, 2011, 03:18 AM

Hi there,

First, make sure the type you added to App_Code is ADO.NET Entity Data Model and not another type.

Once you've followed the wizard and added the tables, defined the model namespace and so on, open the diagram and click somewhere on a blank spot of the design surface outside any object. Then open the Properties Grid for the diagram and look under Code Generation Strategy. What do you have there? It should be set to Default which uses T4 templates to generate the designer file. Your Grid should look like this:

http://imar.spaanjaars.com/Downloads...tWroxModel.png

Cheers,

Imar

alharlow · March 16th, 2011, 09:02 PM

My conceptual entity model looks just like the link you provided except for the namespace, entity container name, and the connection string, which I would expect to be different.

Any ideas?

Thanks in advance.

Imar · March 17th, 2011, 02:54 AM

Quote:

Any ideas?

Not really.... Somehow it seems that Visual Studio is not generating the Code Behind file for the model. Have you tried recreating it from scratch?

Can you zip up your site and send me a copy for me to look at? You can contact me through my site at http://imar.spaanjaars.com/contact to find out my e-mail address.

Cheers,

Imar

alharlow · March 18th, 2011, 12:36 AM

Thanks for your previous suggestion. I was able to remove the Entity stuff and readd and designer.vb code showed up. One wierd thing - the 'factory method' in the vb file didn't have all of the table fields listed in the parameters list (between the '()') and the same table fields were missing in the assignment statments.

Code:

        
Public Shared Function Createpatient_info(ByVal id As Global.System.Int32, ByVal last_name As Global.System.String, ByVal first_name As Global.System.String, ByVal address1 As Global.System.String, ByVal city As Global.System.String, ByVal state As Global.System.String, ByVal zip As Global.System.String, 

' The rest of this list between the () I had to add...

ByVal dob As Global.System.String, ByVal spouse_name As Global.System.String, ByVal insurance_carrier_id As Global.System.String, ByVal HICN As Global.System.String, ByVal pwr_of_attorney As Global.System.String) As patient_info
            Dim patient_info As patient_info = New patient_info
            patient_info.id = id
            patient_info.last_name = last_name
            patient_info.first_name = first_name
            patient_info.address1 = address1
            patient_info.city = city
            patient_info.state = state
            patient_info.zip = zip
'from here down were missing - I had to add...
            patient_info.DOB = dob
            patient_info.spouse_name = spouse_name
            patient_info.insurance_carrier_id = insurance_carrier_id
            patient_info.HICN = HICN
            patient_info.pwr_of_attorney = pwr_of_attorney

            Return patient_info
        End Function

Ok, now for my current issue(s)
1) How do I take a date from a text field and put it in the class for the table? I know it needs a 'cast' of some sort.
2) When I execute the myPatient.SaveChanges() statement it doesn't put anything in the database. Here is the code:

Code:

    Protected Sub bAdd_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles bAdd.Click
        Using myPatient As New PrimusEntities()
            'Dim Patient = (From r In myPatient.patient_info
            '             Where r.id = ID
            '             Select r).SingleOrDefault()
            Dim patient As New patient_info()

            patient.last_name = LastName.ToString
            patient.first_name = FirstName.ToString
            patient.middle_name = MidName.ToString
            patient.address1 = Addr1.ToString
            patient.address2 = Addr2.ToString
            patient.city = City.ToString
            patient.state = State.ToString
            patient.zip = Zip.ToString
            'patient.DOB = DirectCast(DOB.ToString, Date)
            patient.spouse_name = SpouseName.ToString
            patient.insurance_carrier_id = InsurCarrierID.ToString
            patient.HICN = HICN.ToString
            patient.pwr_of_attorney = PwrOfAttorney.ToString

            myPatient.SaveChanges()

            Response.Redirect("patient_add.aspx")

        End Using
    End Sub

Imar · March 18th, 2011, 05:00 AM

Hi there,

You shouldn't have to manually update the designer file yourself. The next time you make a change to the model the file is regenerated and your changes are lost. It looks like EF is using a different database than you think? E.g. an older version without these columns that maybe you added recently?

Quote:

1) How do I take a date from a text field and put it in the class for the table? I know it needs a 'cast' of some sort.

Almost. Cast is used to cast between compatible types. In this case, string and date aren't compatible, so you need Convert instead.

Code:

myDate = Convert.ToDateTime(someControl.Text)

Alternatively, you could use the static DateTime.Parse and DateTime.TryParse methods.

Quote:

2) When I execute the myPatient.SaveChanges() statement it doesn't put anything in the database. Here is the code:

Take a look at the section "Hand-Coding Data Access Pages" that starts at page 555.
In step 6 of the TIO on page 559 you find an example that looks similar to yours. A new Review is created which is then added to the Reviews collection with this code:

Code:

 
myEntities.AddToReviews(myReview)

You need to do something liek this with your object as well. Otherwise, you're just newing up a Patient without telling EF of its existence.

BTW: for your latter two questions, you're better off asking them separately in their own thread. This makes it easier for everyone. It'll also give you more viewers. Even better, post them in a generic ASP.NET 4 category as they are not really directly related to the book: http://p2p.wrox.com/asp-net-4-539/

Cheers,

Imar