从一对多关系中检索实体（Odata）

Question

Summarizing, I have two main tables: Company and Employees , with a one-to-many relationship between them: employees belongs to a company.

The Company entity has a property called Employees, which allows to get the employees who belongs to the specific Company.

If I type in the browser this URL, it works and I get an employees list:

http://domain.com/DynamicsNAV80/OData/Company('whatever')/Employees

Now, I want to retrieve the employees using a Linq query, how can I do it?

I have tried this:

var dataServiceQuery = (DataServiceQuery<Company>)from comp in _context.Company.Expand(comp => comp.WhseEmployee)
                                                  where comp.Name == "whatever"
                                                  select comp.WhseEmployee;

But this is not working for me.

Answer 1

What does that query return, an error or just not the data your looking for? Im not sure if the syntax for querying Odata is different but this is how i would do it any other time.

              var dataServiceQuery = from comp in _context.Company.Expand("WhseEmployees")
                                     where comp.Name == "whatever"
                                     select comp;

Answer 2

Which version of OData are you using?

If it is V4. You can try following code.

var employees = _context.Company.ByKey("whatever").WhseEmployee;

Please refer to Client Delayed Query

If it is V3. You need to query the company first, and then use LoadProperty to send request to /Company('whatever')/WsheEmployee.

var company = _context.Company.Where(c=>c.Name="whatever").First();
dsc.LoadProperty(company, "WsheEmployee");

Answer 3

Finally I could do with this query:

    var dataServiceQuery = (DataServiceQuery<WhseEmployee>)_context.Company.Where(c => c.Name == companyName)
                                                                           .SelectMany(c => c.WhseEmployee);