WCF Data Service expand function need help

Question

Hi,

i am having 3 tables Contents, Tags and ContentTags.

Where ContentTags having PK of Contents and Tags as Fk.

Now my requirement is to populate all the contents with its ContentTags details along with the tags details where Tags ='<any tag>'

currently i am able to populate all the content by using below URI-

https://myservice/WNADataService.svc/Contents()?$expand=ContentTags,ContentTags/Tag

But i am not able to get all the contents for a specific Tag.

 

or can we have something like this

http://services.odata.org/Northwind/Northwind.svc/Orders()/Customer where orderid in (4,5,6,7,8)

 

and also can we have something like this

http://services.odata.org/Northwind/Northwind.svc/Orders(1,2,3,4,5)/Customer

please help me..

 

Answer 1

Hi dexter71,

Welcome!
We will do some more pending research  about your problem and come back as soon as possible, Thanks for understanding.
Have a nice day.

 

---

Alan Chen[MSFT]
MSDN Community Support | Feedback to us
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Answer 2

Hi dexter71,

>>http://services.odata.org/Northwind/Northwind.svc/Orders(1,2,3,4,5)/Customer

Please try: http://services.odata.org/Northwind/Northwind.svc/Orders()?$filter=orderid lt 6&$expand=Customer

I'd like to share a way to get the query URI:

1. Create a client(Console application)

2. Add service reference to console application.

3. Write the query, for example:

 var db = new HospitalContext(new Uri(@"http://localhost:4490/HospitalService.svc"));
            var q = from c in db.Patients.Expand("LabResults")
                    where c.Id < 3
                    select c;

4. set break point after the query, press F5 to debug.

5. you can easy watch the query URI in watch window

Have a nice day.

 

---

Alan Chen[MSFT]
MSDN Community Support | Feedback to us
Get or Request Code Sample from Microsoft
Please remember to mark the replies as answers if they help and unmark them if they provide no help.

Answer 3

Hi dexter71,

 

We don't currently support the ability to filter entity sets which come from expansions.  In the future, you'll be able to do this with the "any" keyword described here: http://www.odata.org/blog/2011/2/15/even-more-any-and-all.

 

In your case, you may want to structure the query so that you get the tags first, like this:

https://myservice/WNADataService.svc/Tags()?$filter=tagvalue eq 'some specific tag'&$expand=Contents

(assuming you have an association from a tag to the Contents table)

 

Hope this helps,

Jen

Answer 4

Hi Dexter,

Not sure if you managed to resolve your problems but, in the case you haven't or anybody else stumbles on this question with the same problem:

 

To expand on a filtered list, I believe the Odata query should be as Alan said. I haven't come across an 'In' function for OData, if you want to extract a user selected list of items I believe the filter needs to besomething like

http://services.odata.org/Northwind/Northwind.svc/Orders()?$filter=OrderID eq 1031 or OrderID eq 34 or OrderID eq 192&$expand=Customer

 

I'm not entirely sure on what the problem is with your Content/Tags scenario, are you after something like this

https://myservice/WNADataService.svc/Contents()?$expand=ContentTags/Tag/Content

?