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missing Navigation property in auto-generated entity class

开发者 https://www.devze.com 2023-02-10 14:40 出处:网络
I am moving my first steps in the Entity Framework 4.0, and I am currently facing an annoying issue.

I am moving my first steps in the Entity Framework 4.0, and I am currently facing an annoying issue.

The authentication/authorization process of my application is based on the standard ASP.NET membership provider, in other words the database is the well-known ASPNETDB.MDF. In this database there are - amongst others - the tables aspnet_Users and aspnet_Roles, which are linked together by the table aspnet_UsersInRoles.

I generated a new "ADO.NET Entity Data Model", I selected Generate from Database, I provided all the necessary parameters, and the wizard generated for me the relative .EDMX file. I named this "SecurityModel". In the aspnet_User entity I can see there is a navigation property that should retrieve all linked Roles, and viceversa.

At this point I added a new "Domain Service", in my case SecurityDomainService. When I was asked, I selected the SecurityModel, and all the tables it contains. Even in this case the wizard generated the SecurityDomainService for me.

Apparently no problems at all. However, I realized that in the entity aspnet_User I have all navigation properties (Membership, Profile, Applications, etc.) but Roles.

I read somewhere that EntityFramework doesnt handle many-to-many relationships. However I can see in my Entity Data Model that an Association exists between aspnet_开发者_开发问答Roles and aspnet_Users, and it is based on aspnet_UsersInRoles. I can also see in the Data Model designer the "Roles" navigation property in the User entity.

So, my question is why has not this navigation property been generated?

Thanks in advance for all your help. Cheers, G.


The problem here is that the aspnet_UsersInRoles table contains only the primary key fields of the tables in the many to many relationship. Entity Framework 'inlines' this table and does not represent it as an entity. Entity Framework handles this fine - it is RIA services that does not support this type of relationship.

Simply adding one extra field to the table will prevent it from being inlined and result in an aspnet_UsersInRoles being generated. This will be supported within RIA Services.

You will need to be careful modifying the aspnet schema to ensure that you do not break any of the stored procedures etc but the addition of a nullable bit column should not cause too much disruption.

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