We Keep Coding

get related data from ms dynamics crm using XRM SDK

I'm trying to retrieve data from crm in a .net application, using the SDK.
I've managed to do simple queries to retrieve lists, but I would now like to get the related entities with items, rather than the ids.
I have tried things like
QueryExpression query = new QueryExpression
{
EntityName = "opportunity",
....
LinkEntity linkEntityAccount = new LinkEntity()
{
LinkFromEntityName = "opportunity",
LinkFromAttributeName = "opportunityid",
LinkToEntityName = "serviceappointment",
LinkToAttributeName = "regardingobjectid",
JoinOperator = JoinOperator.Inner,
Columns = new ColumnSet(new string[] { "scheduledstart", "scheduledend" }),
EntityAlias = "service"
};
query.LinkEntities.Add(linkEntityAccount);
(This will return a collection of entities from the opportunity table)
However the LinkedEntities just put the two columns in the returns entities.
What i would like is (say for this example) is a entity.serviceappointment to be the the entity containing the service appointment entity/data. Instead of in entity there being fields such as service.scheduledstart and service.scheduledend
I have looked at the Relationship and RelationshipQueryCollection things in the SDK but i have been unable to setup a query that will do the query, without first getting the opportunity entities. But it looks like that maybe what I need? I'm not sure.
Is this even possible? Or should I just continue to query entities individually?
Thanks

In the QueryExpression the LinkEntity represents a join. That's why the fields of the joined table are in the Entity row. They can be distinguished from the 'real' entity attributes by the fact that their names are prefixed (including a dot) and their values are wrapped in an AliasedValue object.
It is possible to unwrap them and create strong typed Entity objects, but you will need to write the code yourself.
Alternatively you can consider a few other options:
Query for serviceappointment records and join the opportunity records.
Retrieve opportunity records one by one using the RetrieveRequest and include the query for the related service appointments in the request. (See also this discussion on StackOverflow.)
Create an Action returning all data you need in a convenient OrganizationResponse.

There's no automatic way to get the entire linked entity data (as an Entity object) that I know of (that's not to say it's impossible, mind you).
But I think it'd be a lot easier to just query the data you need in another request.
Find the list of opportunities you need
Use the regarding object IDs as the parameter of an "IN" filter for the second query.

LINQ EF Join query from 2 different data context

I am using LINQ to retrieve data from my EF context as well as from Asp .Net Identity 2.0 - both located in the same MS SQL Server database.
My problem is that LINQ sees them as 2 different cases of data context and is unable to process the query.
"The specified LINQ expression contains references to queries that are associated with different contexts."
What I want to achieve is a simple return of 10 top items (I skip this in the code extract) from EF table, previously sorted by the UserName from ASP .NET Identity table.
I have seen a few cases of this problem on StackOverflow but I was unable to apply any solution in my case.
The preferred solution would be of course not to download all of the table data and do the sorting on the server.
The query in question:
var dbDataSorted = from entry in dbData
join user in this.UserManager.Users
on entry.UserId equals new Guid(user.Id)
orderby user.UserName ascending
select entry;
return dbDataSorted;

I was able to get this to work in my case by using AsEnumerable(). YMMV.
In your case:
var dbDataSorted = from entry in dbData.AsEnumerable()
join user in this.UserManager.Users
on entry.UserId equals new Guid(user.Id)
orderby user.UserName ascending
select entry;
return dbDataSorted;

LINQ and EF are pretty cool. But sometimes, its abstractions don't offer what you need.
Just fall back to base, write the query by hand, put it in a string, run it against yourcontext.YourDbSet with the SqlQuery method, and be done with it.
var query = #"SELECT * FROM dbData as entry
INNER JOIN Users
ON entry.UserId = Users.Id
ORDER BY Users.Username";
yourcontext.dbData.SqlQuery(query);
If the abstractions offered to you don't work with what you need, abusing the abstractions to do something weird is far less clear than using the lower level interface.

You can't use Linq to Entities and Linq to object in one query. It's because when you make query to instance of IQueryable interface, the query will be transformed to SQL, and in SQL you can't use any IEnumerable collection. So you should get data from database (for example dbData.AsEnumerable()).
But if you want do all job on the SQL Server side, the easiest way is to create sql procedure and pass the users table as a parameter. The easiest way to pass users table as xml and than parse it in the procedure on the server side.

If you're using ASP.NET Identity 2 code-first, then your DbContext presumably inherits from IdentityDbContext<>, and so you can access the Users table directly from the context. You don't need to use UserManager to access the users.

NHibernate stored procedure returns data from previous query

I use two stored procedures that return the data with the same structure (list of records of the same type).
I call my method Execute(ISession session) twice. First time for the first stored procedure (it returns correct list of 6 rows). Second time - for the second stored procedure (it returns list of 11 rows, but first 6 rows are from the first request that overwrite the correct rows).
I found
Impact on NHibernate caching for searches with results including calculated value mapped as a formula (e.g. rank)
But I can't use it for IQuery
Any ideas or links how it can be fixed ?
public dynamic Execute(ISession session)
{
var query = session.GetNamedQuery(QueryName)
.SetCacheable(false)
.SetCacheMode(CacheMode.Ignore)
.SetReadOnly(true);
var results = query.List<T>();
return results;
}

I'm going to take a stab at answering this, because I think I have a hunch of what's going on, and I want to set you on the right track. I've made a lot of assumptions here, so please don't be too harsh on me if I was completely wrong with my guesses.
It feels like you're trying to use NHibernate as a tool to simply translate rows into objects. Instead NHibernate is a tool that translates between your object oriented domain model and your relational database domain model. It does a lot more that just turn rows into objects. In particular, the NHibernate feature that you're tripping over here is how NHibernate ensures that within a single NHibernate session, a single row in the database which represents a single entity will correspond to a single instance of an object. It uses its first-level cache to accomplish this.
Let's say you have two queries, QueryA and QueryB. These queries have been constructed so that they each pull from separate tables, TableA and TableB, so really they represent separate entities. However, the queries have also somehow been built so that the result look to NHibernate like the same entity. If QueryA and QueryB happen to return some of the same ids, then NHibernate will combine them into the same instance, so you would see some of the results from QueryA repeated when you run QueryB.
So how do we fix it?
The quick and dirty fix would be to use different sessions for each of those two queries, or throw a session.Clear() in-between them. The more appropriate fix would be to change these named queries so that they actually do return two different entities.

I have the same problem, in first place I resolved the problem with session.Clear() but this solution lead to another bug. I read the response of Daniel and this response I served to detect that the issue is in the stored procedure, the stored procedure did not return an unique identifier and this produced the error when I mapped the ID with nhibernate.

Eager loading of Linq to SQL Entities in a self referencing table

I have 2 related Linq to SQL questions. Please see the image below to see what my Model looks like.
Question 1
I am trying to figure how to eager load the User.AddedByUser field on my User class/table. This field is generated from the relationship on the User.AddedByUserId field. The table is self-referencing, and I am trying to figure out how to get Linq to SQL to load up the User.AddedByUser property eagerly, i.e. whenever any User entity is loaded/fetched, it must also fetch the User.AddedByUser and User.ChangedByUser. However, I understand that this could become a recursive problem...
Update 1.1:
I've tried to use the DataLoadOptions as follows:
var options = new DataLoadOptions();
options.LoadWith<User>(u => u.ChangedByUser);
options.LoadWith<User>(u => u.AddedByUser);
db = new ModelDataContext(connectionString);
db.LoadOptions = options;
But this doesn't work, I get the following exception on Line 2:
System.InvalidOperationException occurred
Message="Cycles not allowed in LoadOptions LoadWith type graph."
Source="System.Data.Linq"
StackTrace:
at System.Data.Linq.DataLoadOptions.ValidateTypeGraphAcyclic()
at System.Data.Linq.DataLoadOptions.Preload(MemberInfo association)
at System.Data.Linq.DataLoadOptions.LoadWith[T](Expression`1 expression)
at i3t.KpCosting.Service.Library.Repositories.UserRepository..ctor(String connectionString) in C:\Development\KP Costing\Trunk\Code\i3t.KpCosting.Service.Library\Repositories\UserRepository.cs:line 15
InnerException:
The exception is quite self-explanatory - the object graph isn't allowed to be Cyclic.
Also, assuming Line 2 didn't throw an exception, I'm pretty sure Line 3 would, since they are duplicate keys.
Update 1.2:
The following doesn't work either (not used in conjuction with Update 1.1 above):
var query = from u in db.Users
select new User()
{
Id = u.Id,
// other fields removed for brevityy
AddedByUser = u.AddedByUser,
ChangedByUser = u.ChangedByUser,
};
return query.ToList();
It throws the following, self-explanatory exception:
System.NotSupportedException occurred
Message="Explicit construction of entity type 'i3t.KpCosting.Shared.Model.User' in query is not allowed."
I am now REALLY at a loss on how to solve this. Please help!
Question 2
On every other table in my DB, and hence Linq to SQL model, I have two fields, Entity.ChangedByUser (linked to Entity.ChangedByUserId foreign key/relationship) and Entity.AddedByUser (linked to Entity.AddedByUserId foreign key/relationship)
How do I get Linq to SQL to eageryly load these fields for me? Do I need to do a simple join on my queries?, or is there some other way?
Linq to SQL eager loading on self referencing table http://img245.imageshack.us/img245/5631/linqtosql.jpg

Any type of cycles just aren't allowed. Since the LoadWith<T> or AssociateWith<T> are applied to every type on the context, there's no internal way to prevent an endless loop. More accurately, it's just confused on how to create the SQL since SQL Server doesn't have CONNECT BY and CTEs are really past what Linq can generate automatically with the provided framework.
The best option available to you is to manually do the 1 level join down to the user table for both of the children and an anonymous type to return them. Sorry it's not a clean/easy solution, but it's really all that's available thus far with Linq.

Maybe you could try taking a step back and seeing what you want to do with the relation? I'm assuming you want to display this information to the user in e.g. "modified by Iain Galloway 8 hours ago".
Could something like the following work? :-
var users = from u in db.Users
select new
{
/* other stuff... */
AddedTimestamp = u.AddedTimestamp,
AddedDescription = u.AddedByUser.FullName,
ChangedTimestamp = u.ChangedTimestamp,
ChangedDescription = u.ChangedByUser.FullName
};
I've used an anonymous type there for (imo) clarity. You could add those properties to your User type if you preferred.
As for your second question, your normal LoadWith(x => x.AddedByUser) etc. should work just fine - although I tend to prefer storing the description string directly in the database - you've got a trade-off between your description updating when ChangedByUser.FullName changes and having to do something complicated and possibly counterintuitive if the ChangedByUser gets deleted (e.g. ON DELETE CASCADE, or dealing with a null ChangedByUser in your code).

Not sure there is a solution to this problem with Linq to Sql. If you are using Sql Server 2005 you could define a (recursive like) Stored Procecdure that uses common table expressions to get the result that you want and then execute that using DataContext.ExecuteQuery.

Retrieving a tree structure from a database using LINQ

I have an organization chart tree structure stored in a database.
Is is something like
ID (int);
Name (String);
ParentID (int)
In C# it is represented by a class like
class Employee
{
int ID,
string Name,
IList < Employee> Subs
}
I am wondering how is the best way to retrieve these values from the database to fill up the C# Objects using LINQ (I am using Entity Framework)
There must be something better than making a call to get the top level then making repeated calls to get subs and so on.
How best to do it?

You can build a stored proc that has built in recursion. Take a look at http://msdn.microsoft.com/en-us/library/ms190766.aspx for more info on Common Table Expressions in SQL Server
You might want to find a different (better?) way to model your data. http://www.sqlteam.com/article/more-trees-hierarchies-in-sql lists a popular way of modeling hierarchical data in a database. Changing the modeling can allow you to create queries that can be expressed without recursion.

If you're using SQL Server 2008, you could make use of the new HIERARCHYID feature.
Organizations have struggled in past
with the representation of tree like
structures in the databases, lot of
joins lots of complex logic goes into
the place, whether it is organization
hierarchy or defining a BOM (Bill of
Materials) where one finished product
is dependent on another semi finished
materials / kit items and these kit
items are dependent on another semi
finished items or raw materials.
SQL Server 2008 has the solution to
the problem where we store the entire
hierarchy in the data type
HierarchyID. HierarchyID is a variable
length system data type. HierarchyID
is used to locate the position in the
hierarchy of the element like Scott is
the CEO and Mark as well as Ravi
reports to Scott and Ben and Laura
report to Mark, Vijay, James and Frank
report to Ravi.
So use the new functions available, and simply return the data you need without using LINQ. The drawback is you'll need to use UDF or stored procedures for anything beyond a simple root query:
SELECT #Manager = CAST('/1/' AS hierarchyid)
SELECT #FirstChild = #Manager.GetDescendant(NULL,NULL)

I'd add a field to the entity to include the parent ID, then I'd pull the whole table into memory leaving the List subs null. Id then iterate through the objects and populate the list using linq to objects. Only one DB query so should be reasonable.

An Entity Framework query should allow you to include related entity sets, though in a unary relationship, not sure how it would work...
Check this out for more information on that: http://msdn.microsoft.com/en-us/library/bb896272.aspx

Well... even with LINQ you will need two queries, because any single query will duplicate the main employee and thus will result in multiple employees (that are really the same) being created... However, you can hide this a bit with linq when you create the object, that's when you would execute the second query, something like this:
var v = from u in TblUsers
select new {
SupervisorName = u.DisplayName,
Subs = (from sub in TblUsers where sub.SupervisorID.Value==u.UserID select sub.DisplayName).ToList()
};