Home/ Questions/Q 1066287
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-05-16T19:59:33+00:00

For a new project I’m trying to create my business classes first and create

  • 0

For a new project I’m trying to create my business classes first and create the real database tables later. Therefore I’m using the Entity Framework 4 Designer. A created a new “ADO.Net Entity Data model” file, with the extension .edmx.

I created two Entities:
alt text

I want to add a 1 to nc relation between Product -> Group. If I’d created the MSSQL database first, I would have added a column IDGroup to the Table Product and referenced Product.IDGroup to Group.IDGroup. As far as I can see, I can’t add such association in the designer if I add a new Property called IDGroup to the Product Entity

This is how I add the mapping:
alt text

Which results in:
alt text

Now the part what this question is about: If I add two tables from an existing MSSQL database to the edmx file, I’ll get the compile error:

Error 3027: No mapping specified for the following EntitySet/AssociationSet - GroupSet, ProductSet

What does that error mean and what must I do to fix this?
If I delete those two tables, I’ll receive a warning instead:

Error 2062: No mapping specified for instances of the EntitySet and AssociationSet in the EntityContainer myContainer.

Something tells me, I’m doing this all wrong and this is just basic stuff. How can I do it right?

Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    I just ran into this myself & when I Googled it (I hit your question).

    I was able to double click on the line (association line) in the designer. Fill in the properties there and I got it working.

    I also had to close VS and re-open it to get some of the errors reported to go away…

    Can’t say this is the correct answer – just fumbling around and seeming to get results.

    • 0