c# - How to get ObjectResult from Entity Framework using a list of Identities

Question

I have a HashSet of Identity values that I need to use as the query values to return a ObjectResult from the Entity Framework

Here's the HashSet:

HashSet<int> officeIds = new HashSet<int>();

Here's the query that I'm trying to run more or less:

ObjectResult<FilingOffice> offices = ctx.FilingOffice.Where(office => office IN officeIds.ToList());

The "office => office IN officeIds.ToList()" part of the above is what I can't get to work and haven't found any samples on the web for returing objects given a list of primary keys.

ctx is the System.Data.Objects.ObjectContext

Answer 1

The examples others have given won't work in the Entity Framework today, because you can't mix client and serverside enumerations in LINQ 2 Entities.

Instead you need to build an OR expression, manually.

I run a series of EF Tips and this tip shows you how to build an OR expression up.

Hope this helps

Alex