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Possible to add a condition for linked table fields in LINQ

Can someone suggest me a solution to add condition for reference table items in linq.
I have a master table called TourPackage, which include
public class TourPackage{
public int TourID { get; set; }
public string TourName { get; set; }
public List<IncludedItems> IncludedItems { get; set; }
}
Every tour package contain some selected items reference like
public class IncludedItems {
public int TourID { get; set; }
public int IncludedID { get; set; }
public Included Included { get; set; }
}
All included item should have a reference to Included table for lookup reference
public class Included {
public int IncludedID { get; set; }
public string IncludedValue { get; set; }
}
now i have set of IncludedID like [1,2,3], Is it possible to filter TourPackage based on IncludedID.
Thanks in advance

You can use following code
I have sample array(i.e example) which contains ID's we check if current Id(i.e ele.Included.IncludedID) is present in the array of id's.
listex.Where(x => x.IncludedItems.Any(ele => example.Contains(ele.Included.IncludedID))).ToList();
sample:-
int[] example = new int[3];
example[0] = 123;
example[1] = 456;
example[2] = 789;
List<TourPackage> listex = new List<TourPackage>();
List<TourPackage> filterList = listex.Where(x => x.IncludedItems.Any(ele => example.Contains(ele.Included.IncludedID))).ToList();

Have you tried using something like:
var myIds = new List<int> {123,456};
var result = context.TourPackages
.Where(x => x.IncludedItems.Any(a => a.Included !=null && myIds.Contains(a.Included.IncludedId)))
.ToList();
You might have to include some relations manually depending if you're lazy loading is setup or not.
More info at https://msdn.microsoft.com/en-us/library/jj574232(v=vs.113).aspx

How to query multiple inherited sub-classes in a single query in Entity Framework

I have a big problem of querying diverse types of inherited subentities in a single query in Entity Framework. My essential aim is providing all of my data model structure in a single JSON string by eager loading. And the tricky point is "the inherited subclasses may contain another inherited subclass". The example seen below will clearly explain the situation.
Assume that I have a simple class structure like this:
public class Teacher
{
public int id { get; set; }
public string fullname{ get; set; }
//navigation properties
public virtual HashSet<Course> courses{ get; set; }
}
public class Course
{
public int id { get; set; }
public string coursename{ get; set; }
//foreign keys
public int TeacherId{ get; set; }
//navigation properties
public virtual Teacher teacher{ get; set; }
public virtual HashSet<Course> prerequisites{ get; set; }
}
Course has some subclasses GradedCourse and UngradedCourse
B1 or B2 may have a list of subentities consists of entities of types B1 or B2.
public class GradedCourse : Course
{
public string gradeType{ get; set; }
}
public class UngradedCourse: Course
{
public string successMetric { get; set; }
}
Now by this structure I want to provide a JSON structure from my WEBApi yielding list of Teacher objects including both GradedCourse and UngradedCourse with their subentities and specific fields. I have a query like this but it does not compile
db.Teachers.Select(t => new
{
t.id,
t.fullName
courses = t.courses.OfType<GradedCourses>()
.Select(g => new
{
id = g.id,
coursename = g.coursename,
prerequisites = g.prerequisites, // this is the list of other subentities
gradeType = g.gradeType
}
).Concat(t.courses.OfType<UngradedCourses>()
.Select(u => new
{
id = u.id,
coursename = u.coursename,
prerequisites = g.prerequisites, // this is the list of other subentities
successMetric= u.successMetric // subclass specific field
}
)
)
}
)
The problem is concating two different types of objects (they have different fields which is not possible for SQL UNION)
How can I handle this? Any help will open my mind. Thanks in advance for the professionals :)

It does not compile because the element type of 2 sets is not the same. So you just need to make them the same before being able to do anything:
db.Teachers.Select(t => new
{
t.id,
t.fullName
courses = t.courses.OfType<GradedCourses>()
.Select(g => new
{
id = g.id,
coursename = g.coursename,
prerequisites = g.prerequisites, // this is the list of other subentities
isGradedCourse = true,
gradeTypeOrMetric = g.gradeType
}).Concat(t.courses.OfType<UngradedCourses>()
.Select(u => new
{
id = u.id,
coursename = u.coursename,
prerequisites = g.prerequisites, // this is the list of other subentities
isGradedCourse = false,
gradeTypeOrMetric= u.successMetric // subclass specific field
}))
//finally select what of your choice
.Select(e => new {
id = e.id,
coursename = e.coursename,
prerequisites = e.prerequisites,
gradeType = e.isGradedCourse ? e.gradeTypeOrMetric : "",
successMetric = e.isGradedCourse ? "" : e.gradeTypeOrMetric
})
});
You still benefit the query being executed on server side without having to pull all teachers to local (and then being able to cast the entities - which is not supported in LinqToEntity query).

How to order Nested Collections in Linq and EF

i would like to make a treelistview for my Data.
Tree should look like this
Accounts
-> Providers
-> Accounts
public sealed class AccountRoot
{
public AccountRoot()
{
Providers = new Collection<Hoster>();
}
public long AccountRootId { get; set; }
public ICollection<Hoster> Providers { get; set; }
}
public sealed class Hoster
{
public Hoster()
{
Accounts = new Collection<Account>();
}
[Key]
public long HosterId { get; set; }
public long AccountRootId { get; set; }
public string Name { get; set; }
public ICollection<Account> Accounts { get; set; }
}
public sealed class Account
{
[Key]
public long AccountId { get; set; }
public long HosterId { get; set; }
public Hoster Hoster { get; set; }
public string Name { get; set; }
}
I would like to order my query.
should be sth like
Accounts
Providers A-Z
Accounts A-Z
what i got until now is..
var query = _entity.AccountRoot.Local
.Select(x => new AccountRoot()
{
AccountRootId = x.AccountRootId,
Providers = x.Providers.OrderBy(y => y.Name).ToList()
}).ToList();
What is missing is the orderby for the next nested collection.
Thank you for your help ! :-)

It can be a bit different approaches depending on if you already have a result set, and want to just sort it in code, or if you want to construct IQueryable<> for EF which will be successfully compiled to SQL and executed with actual sorting in database.
First, assume you already have the collection in code. In this case, you have object AccountRoot, which contains collection of Providers, each of which has collection of Accounts. Obviously, you cannot return the same objects, as you need to reorder collection properties, so all you need is to just construct new ones. I would just sort the collections, but you could construct completely new entities, if you need:
var query = ...
.Select(x => new AccountRoot
{
// add copy properties here
// ....
Providers = x.Providers
.Select(y =>
{
// Here we can construct completely new entity,
// with copying all properties one by one,
// or just reorder existing collection as I do here
var result = y;
result.Accounts = y.Accounts.OrderBy(z => z.Name).ToArray();
return result;
})
.OrderBy(y => y.Name)
.ToArray()
})
.ToArray();
Second case, if you need to get it directly from SQL, is a bit different, as you cannot use all that var result = ...; ... return result stuff in lambda - it won't compile to SQL. But idea is the same - you need to construct projection from data sets. It should be something like this:
var query = ...
.Select(x => new AccountRoot
{
AccountRootId = x.AccountRootId,
// Other properties to copy
// ...
Providers = x.Providers
.Select(y => new Hoster
{
HosterId = y.HosterId,
// Other properties to copy
// ...
Accounts = y.Accounts.OrderBy(z => z.Name).ToArray(),
})
.OrderBy(y => y.Name)
.ToArray()
})
.ToArray();

Lambda expression - select single object with a IEnumerable<> property

Is it possible to select a single object and populate a containing IEnumerable property with a single Lambda expression?
Something like this:
var someViewModel = _repository.Table.Where(x => x.Id == someId)
.Select(new ListViewModel(){
GroupId = x.Group.Id,
GroupTitle = x.Group.Title
List = ?? // Select new SubViewModel and add it to IEnumerable<SubViewModel>
})
The result I'm after is a new object (ListViewModel in this case) that contains 3 properties. "List" being a collection of newly selected objects.
Is this possible? Am I coming at this from the wrong angle?
Thanks!
Update:
Let me try again :) Keep in mind that my naming is fictional here. Given the following two classes I would like to construct a DB query using a Lambda expression which creates a single "ListViewModel" that contains a collection of "SubViewModel". Does this help clarify?
public class SubViewModel
{
public int Id { get; set; }
public string Title { get; set; }
}
public class ListViewModel
{
public int GroupId { get; set; }
public string GroupTitle { get; set; }
public IEnumerable<SubViewModel> List { get; set; }
}

I'm not sure if I understand your question correctly but here is what I am thinking, you need to create a new IEnumberable and add the item to that collection.
var someViewModel = _repository.Table.Where(x => x.Id == someId)
.Select(new ListViewModel()
{
GroupId = x.Group.Id,
GroupTitle = x.Group.Title
List = new List<SubViewModel> { new SubViewModel(x) }
});

RavenDB cross entity query matching on non-identifier property

I have the following entity collections in RavenDB:
public class EntityA
{
public string Id { get; set; }
public string Name { get; set; }
public string[] Tags { get; set; }
}
public class EntityB
{
public string Id { get; set; }
public string Name { get; set; }
public string[] Tags { get; set; }
}
The only thing shared is the Tags collection: a tag of EntityA may exist in EntityB, so that they may intersect.
How can I retrieve every EntityA that has intersecting tags with EntityB where the Name property of EntityB is equal to a given value?

Well, this is a difficult one. To do it right, you would need two levels of reducing - one by the tag which would expand out your results, and another by the id to collapse it back. Raven doesn't have an easy way to do this.
You can fake it out though using a Transform. The only problem is that you will have skipped items in your result set, so make sure you know how to deal with those.
public class TestIndex : AbstractMultiMapIndexCreationTask<TestIndex.Result>
{
public class Result
{
public string[] Ids { get; set; }
public string Name { get; set; }
public string Tag { get; set; }
}
public TestIndex()
{
AddMap<EntityA>(entities => from a in entities
from tag in a.Tags.DefaultIfEmpty("_")
select new
{
Ids = new[] { a.Id },
Name = (string) null,
Tag = tag
});
AddMap<EntityB>(entities => from b in entities
from tag in b.Tags
select new
{
Ids = new string[0],
b.Name,
Tag = tag
});
Reduce = results => from result in results
group result by result.Tag
into g
select new
{
Ids = g.SelectMany(x => x.Ids),
g.First(x => x.Name != null).Name,
Tag = g.Key
};
TransformResults = (database, results) =>
results.SelectMany(x => x.Ids)
.Distinct()
.Select(x => database.Load<EntityA>(x));
}
}
See also the full unit test here.
There is another approach, but I haven't tested it yet. That would be to use the Indexed Properties Bundle to do the first pass, and then map those results for the second pass. I am experimenting with this in general, and if it works, I will update this answer with the results.