Problem with Try It Out in Chapter 17, Page 641

awhitsel · December 17th, 2013, 04:56 PM

In step 2 of the Try It Out, it says to Open the ADO.NET Entity Data Model file PlanetWrox.edmx from the App_Code folder, right-click an empty space in the designer, and choose Update Model from Database. Wait until VWD has analyzed your database and click Finish.

When I did this step an Update Wizard window appears on the screen. I click on the Finish button in this window. After that, I received an error stating "Error 1109: Property 'PhotoAlbumId' is not mapped." Also, the following occurred:

* In the PhotoAlbum block, an extra navigation property called Pictures_1 appeared.
* In the Picture block, an extra field called PhotoAlbumID (I already had a field in that table called PhotoAlbumId) appeared as well as an extra navigation property called PhotoAlbum_1.

This is affecting my ability to complete this exercise. Any assistance will be greatly appreciated. Thank you.

Imar · December 17th, 2013, 05:05 PM

Hi there,

Can you check your database and make sure that:

1. Each table has a column called Id, which is set as the primary key and an identity.
2. You correctly created a relationship between PhotoAlbum.Id and Picture.PhotoAlbumId and between Genre.Id and Review.GenreId.

It sounds like something is wrong with your database schema but it's hard to tell what.

Cheers,

Imar

awhitsel · December 18th, 2013, 09:03 AM

Confirmed on both counts.

I have an Id field in all tables.

I have a one-to-many relationship on the Genre and Review tables with Genre.Id being the "one" and Review.GenreId being the "many".

Also, I have a one-to-many relationship on the PhotoAlbum and Picture tables with PhotoAlbum.Id being the "one" and Picture.PhotoAlbumId being the "many".

When I perform Step 2 it adds an navigation property to the PhotoAlbum (called "Picture") and Picture (called "PhotoAlbum_1") tables, I get a duplicate association and I get "Error 11009: Property 'PhotoAlbumId' is not mapped".

When I undo the operation, the duplicate navigation properties and the duplicate association go away, but the error message stays on.

Imar · December 18th, 2013, 09:23 AM

Can you send me a zipped version of the site (and database) by e-mail? Then I'll see if I can figure out what's wrong. You can find my e-mail address in the Introduction section of the book.

Cheers,

Imar

Imar · December 18th, 2013, 10:51 AM

Files received, thank you.

Did you maybe rename the PhotoAlbumId to PhotoAlbumID column in the Pictue table or vice versa? It looks the Picture class has two properties with almost the same name except for the capitalization.

What if you remove all entities from the diagram, save it, and then add them again?

Imar

awhitsel · December 18th, 2013, 11:06 AM

I got the diagram to work again.

I removed all of the tables and did "Update Model from Database" and re-inserted the tables and associations that way.

Thank you for your assistance.

Imar · December 18th, 2013, 11:41 AM

Excellent; glad it's working.

Cheers,

Imar