Problem with Linq query and SingleTableInheritance

 Hi,

I have got the follwing domain model

Person:
FirstName,
LastName,
Communications (a list of PersonCommunication)

PersonCommunication:
Value
ComType (discriminator field)

Phone inherites from PersonCommunication
(no more fields)

EMail inherites from PersonCommunication
(no more fields)

WebSide  inherites from PersonCommunication
(no more fields)

I want to get a list of all Persons which have a WebSide:

List<Person> persons = (from c in uow.PersonCommunications
                                     where
                                       c is WebSide
                                     select
                                       c.Person
                                     )
                                     .Distinct()
                                     .ToList();

That works. What is not working is:

persons = (

from p in uow.People
                 from c in p.Communications
                 where
                   c is WebSide
                 select 
                   p
                 )
                 .Distinct()
                 .ToList();

Error message "Query Error: Could not find field [ComType] on model [Person]"
Sure, that field ist part of the class PersonCommunication.

I now want to have a list of persons with the FirstName like "%f%" and having a WebSide:

List<Person> persons = (from c in uow.PersonCommunications
                                     where
                                       c is WebSide
                                       &&
                                       c.Person.FirstName.Contains("f")
                                     select
                                       c.Person
                                     )
                                     .Distinct()
                                     .ToList();

Error Message translated from german:
The Object of type "Mindscape.LightSpeed.Querying.PathExpression" can't be converted to type "Mindscape.LightSpeed.Querying.IdentifierExpression".

Can someone give me a hint how to query the domain model?

Hi Sörnt,

Rather than using c is WebSide have a look at using the .OfType extension method to achieve the same result. The second issue looks more like a bug, so I will have a look at if we can create a repro here for this behavior.

Jeremy

Hi Jeremy,

thank you for having a look at my issue. I attached the test project and the SQL script (MS SQL 2005) for creating the tables.

Kind regards,
Sörnt

Hi Jeremy,

I installed the latest version "LightSpeed30Professional-20100330.msi".
And my query for:

List<Person> persons;

persons = (from
                    c in uow.PersonCommunications
                  where
                    c is WebSide
                    &&
                    c.Person.FirstName.Contains("s")
                  select
                    c.Person
                )
               .Distinct()
                .ToList();

Is working now :-)

Thank you very much.

Kind regards,

Sörnt