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How to include two object inside the same select on Linq MVC5

I do have a complex query to select a full object called Performance
The Performance relationship with others objects is:
Performance has a list of Index
Index has a list of SubIndex
SubIndex has a list of Indicator
Indicator has a list of Item
Item relationship with Spot and Measurement:
Item has one Spot and one Measurement
The query below returns exactly what I want, but I would like to include the Spot and Measurement to the Item object.
return _context.Performance.Include(i => i.Indexes
.Select(s => s.SubIndexes
.Select(d => d.Indicators
.Select(t => t.Items))))
.SingleOrDefault(p => p.Id == id);
I have tried the query below and it is returning the Measurement object. How to include the Spot object?
return _context.Performance.Include(i => i.Indexes
.Select(s => s.SubIndexes
.Select(d => d.Indicators
.Select(t => t.Items.Select(tm => tm.Measurement)))))
.SingleOrDefault(p => p.Id == id);

You could add second Include too;
return _context.Performance.Include(i => i.Indexes
.Select(s => s.SubIndexes
.Select(d => d.Indicators
.Select(t => t.Items.Select(tm => tm.Measurement)))))
.Include(i => i.Indexes
.Select(s => s.SubIndexes
.Select(d => d.Indicators
.Select(t => t.Items.Select(tm => tm.Spot)))))
.SingleOrDefault(p => p.Id == id);

NHibernate and MySql Missing column Exception

From time to time my web application begins throwing the following errors.
Using NHibernate 4.0.0.4000 and MySql.Data 6.8.3
Stack Trace
ERROR [(null)] - Message:could not execute query
NHibernate log
NHibernate.Util.ADOExceptionReporter WARN - System.IndexOutOfRangeException: Could not find specified column in results:
Once once of these errors occur it begins to happen frequently until the web application is restart.
It's odd that it only happens to some users and not all. Also I noticed in this particular log message the values of p4 and p5 should be swapped.
Is this an issue with the query cache?
Does anyone have some insight into why this is happening?
If it helps here is the gnarly query (but I see this error on much simpler queries as well)
FunderInfoViewModel funderDto = null;
Funder funderAlias = null;
Contact contactAlias = null;
var totalOpportunitiesAwardedCount = QueryOver.Of<Opportunity>()
.Where(o => o.Funder.Id == funderAlias.Id)
.And(o => o.Status == OpportunityStatus.Awarded || o.Status == OpportunityStatus.AwardedClosed)
.SelectList(list => list
.SelectCount(o => o.Id));
var totalOpportunitiesAwardedSum = QueryOver.Of<Opportunity>()
.Where(o => o.Funder.Id == funderAlias.Id)
.And(o => o.Status == OpportunityStatus.Awarded || o.Status == OpportunityStatus.AwardedClosed)
.SelectList(list => list
.SelectSum(o => o.AmountAwarded));
var totalOpportunitiesCount = QueryOver.Of<Opportunity>()
.Where(o => o.Funder.Id == funderAlias.Id)
.SelectList(list => list
.SelectCount(o => o.Id));
IEnumerable<FunderInfoViewModel> funders = _session.QueryOver(() => funderAlias)
.Left.JoinAlias(f => f.Contacts, () => contactAlias, x => x.IsDefault)
.Where(o => o.Organization.Id == organizationId)
.SelectList(list => list
.Select(x => x.Id)
.WithAlias(() => funderDto.Id)
.Select(x => x.Name)
.WithAlias(() => funderDto.Name)
.Select(x => x.Description)
.WithAlias(() => funderDto.Description)
.Select(x => x.AreasOfInterest)
.WithAlias(() => funderDto.AreasOfInterest)
.Select(x => x.Type)
.WithAlias(() => funderDto.FunderType)
.Select(x => x.TaxId)
.WithAlias(() => funderDto.TaxId)
.Select(x => x.PhoneNumber)
.WithAlias(() => funderDto.PhoneNumber)
.Select(x => x.FaxNumber)
.WithAlias(() => funderDto.FaxNumber)
.Select(x => x.EmailAddress)
.WithAlias(() => funderDto.EmailAddress)
.Select(x => x.Website)
.WithAlias(() => funderDto.Website)
.Select(x => x.CustomLink)
.WithAlias(() => funderDto.CustomLink)
.Select(x => x.MinimumFundingRange)
.WithAlias(() => funderDto.MinimumFundingRange)
.Select(x => x.MaximumFundingRange)
.WithAlias(() => funderDto.MaximumFundingRange)
.Select(() => contactAlias.FirstName)
.WithAlias(() => funderDto.PrimaryContactFirstName)
.Select(() => contactAlias.LastName)
.WithAlias(() => funderDto.PrimaryContactLastName)
.Select(() => contactAlias.Title)
.WithAlias(() => funderDto.PrimaryContactTitle)
.SelectSubQuery(totalOpportunitiesAwardedCount)
.WithAlias(() => funderDto.AwardedOpportunitiesCount)
.SelectSubQuery(totalOpportunitiesAwardedSum)
.WithAlias(() => funderDto.AwardedOpportunitiesValue)
.SelectSubQuery(totalOpportunitiesCount)
.WithAlias(() => funderDto.OpportunitiesCount)
)
.OrderBy(f => f.Name)
.Asc
.TransformUsing(Transformers.AliasToBean<FunderInfoViewModel>())
.List<FunderInfoViewModel>();

Ok got the problem. Its because some of the arguement you are passing in your prepared statement is null, thats why this error. I had similar issue earlier and i solved it by checking only if it is not null add it in query filtering.
Also there is another possibility of row lock by any other query. Are you using lock in mysql query?
2nd problem seems like see the solution stated below
https://forums.asp.net/t/1230295.aspx?IDataReader+Could+not+find+specified+column+in+results+

How to factorize a Linq request with multiple includes?

I want to simplify a linq Query that contains multiple includes.
My model is simple: a site is linked to one contract, that is linked to one client. On that client I need to get with a single request the telephones, mails and honorifics (appelRef).
I want a single request because behind the request is translated by entity framework into a SQL Server request.
Here is the linq request:
var search =
from IMT.Site s in imtContext.IMTObjects.OfType<IMT.Site>()
.Include(
s => s.LienContratSiteRef
.Select(l => l.Contrat)
.Select(c => c.LienContratClientRef
.Select(l => l.Client)
.Select(cl => cl.Telephones ) ) )
.Include(s => s.LienContratSiteRef
.Select(l => l.Contrat)
.Select(c => c.LienContratClientRef
.Select(l => l.Client)
.Select(cl => cl.Mails ) ) )
.Include(s => s.LienContratSiteRef
.Select(l => l.Contrat)
.Select(c => c.LienContratClientRef
.Select(l => l.Client)
.Select(cl => cl.AppelRef ) ) )
where s.Reference.ToString() == siteId
select s;
Yor can notice the block
.Include(
s => s.LienContratSiteRef
.Select(l => l.Contrat)
.Select(c => c.LienContratClientRef
.Select(l => l.Client)
..is repeated three time. Is ther a way to factorize that code block ?
Update: there are intermedray objects LienContratSiteRef and LienContratClientRef and relationships are 0 - *, so that LienContratSiteRef.Contrat and LienContratClientRef.Client are collections.
I also tried:
.Include(
s => s.LienContratSiteRef
.Select(l => l.Contrat)
.Select(c => c.LienContratClientRef
.Select(l => l.Client)
.Select(cl => new { Tels = cl.Telephones, Mail = cl.Mails, Appel = cl.AppelRef} ) ) )
but It results with a runtime error:
The Include path expression must refer to a navigation property
defined on the type.

The s => ... inside the include could be refactored into a delegate, then just .Include that delegate multiple times.
It looks like the signature would be Func<Site, IEnumerable<Client>>?
E.g.
static IEnumerable<Client> Foo(Site site) => site.LienContratSiteRef
.Select(l => l.Contrat)
.Select(c => c.LienContratClientRef
.Select(l => l.Client)

String-based Chaining
The Include() method supports a dot-delimited string parameter which can be used to pull an complete graph of objects down as opposed to making multiple chained select calls:
.Include("LienContratSiteRif.Contrat.LienContratClientRef.Client")
From there, if you wanted to include multiple additional properties, I believe that you could have another include for those sub properties:
.Include("LienContratSiteRif.Contrat.LienContratClientRef.Client, Client.Telephones, ...")
Lambda-based Chaining
You should be able to accomplish something similar by chaining your lambda-based includes into a single Include() call as well using:
.Include(c => LienContratSiteRif.Contrat.LienContratClientRef.Client)

It looks like you're trying to make an entity framework projection!
A project allows you to select only the properties that you want to return. (just like a SQL Select)
To use a projection, your code should roughly look like this:
var search = imtContext.IMTObjects.OfType<IMT.Site>()
.Where(s => s.Reference.ToString() == siteId)
.Select(s => new {
Telephones = s.LienContratSiteRef.Contrat.Select(c => c.LienContratClientRef.Client.Select(cli => cli.Telephones),
Mails = s.LienContratSiteRef.Contrat.Select(c => c.LienContratClientRef.Client.Select(cli => cli.Mails),
AppelRef = s.LienContratSiteRef.Contrat.Select(c => c.LienContratClientRef.Client.Select(cli => cli.AppelRef)
}).ToList();
If Telephones, Mails, AppelRefare also collections, then you can do aggregate the collections together like this in memory after the query has been run:
var telephones = search.SelectMany(x => x.Telephones).ToList();
var mails = search.SelectMany(x => x.Mails).ToList();
var appelRefs = search.SelectMany(x => x.AppelRef).ToList();

Nhibernate Group By and Alias To Bean

I have been struggling to get an old query translated to Nhibernate.
We are upgrading an old project from Nhibernate 2 to the latest version.
I am using the QueryOver syntax since Linq wasn't an option because of the complexity of the queries (advice of a colleague).
I want to query the DB (Oracle) to get some results which have to be grouped.
As result I need a grouped collection of my DTO. I also noticed that nhibernate has trouble translating to a DTO with complex properties (nested DTO's)
To fix this I found this topic. This works great but I am not a fan of the magic strings...
I will add some code snippets of how my monster query is looking at this moment.
Problem is I can't seem to figure out how to add a group by without breaking everything else. So I would want to group on a property but still have the DTO in my results. Something like:
ILookup<int,IEnumerable<NieuwePrintopdrachtenInfo>>
Any help would be welcome.
Sorry the variables and classes are in Dutch -_-
SYNUITGAANDEBRIEF uitgaandebrief = null;
SYNAANVRAAG joinedAanvraag = null;
SYNDOSSIER joinedDossier = null;
SYNVERBRUIKSADRES joinedVerbruiksAdres = null;
SYNEAN joinedEan = null;
SYNCTENERGIETYPE joinedEnergieType = null;
SYNBRIEFBESTEMMELINGEN joinedBriefBestemmeling = null;
SYNCTBRIEFTYPE joinedBriefType = null;
SYNCTBRIEFSTATUS joinedBriefStatus = null;
SYNCONTACTPERSOON joinedContactpersoon = null;
SYNCTCONTACTPERSOONTYPE joinedBestemmelingType = null;
SYNCTVERZENDMODUSTYPE joinedVerzendModus = null;
SYNCTCONTACTPERSOONTYPE joinedContactpersoonType = null;
SYNCTTAAL joinedContactpersoonTaal = null;
SYNTOEWIJZVERBRUIKVERANT joinedVerbruiksVerantw = null;
SYNCTPROFIELGROEP joinedProfielGroep = null;
var baseQuery = SessionHandler.CurrentSession.QueryOver(() => uitgaandebrief)
.JoinAlias(() => uitgaandebrief.AANVRAAGCollection, () => joinedAanvraag)
.JoinAlias(() => joinedAanvraag.DOSSIER, () => joinedDossier)
.JoinAlias(() => joinedDossier.VERBRUIKSADRES, () => joinedVerbruiksAdres)
.JoinAlias(() => joinedAanvraag.EAN, () => joinedEan)
.JoinAlias(() => joinedEan.CtEnergietype, () => joinedEnergieType)
.JoinAlias(() => uitgaandebrief.BRIEFBESTEMMELINGENCollection, () => joinedBriefBestemmeling)
.JoinAlias(() => uitgaandebrief.CtBriefType, () => joinedBriefType)
.JoinAlias(() => uitgaandebrief.CtBriefStatus, () => joinedBriefStatus)
.JoinAlias(() => joinedBriefBestemmeling.CONTACTPERSOONCollection, () => joinedContactpersoon, JoinType.LeftOuterJoin)
.JoinAlias(() => joinedBriefBestemmeling.CtContactPersoonType, () => joinedBestemmelingType, JoinType.LeftOuterJoin)
.JoinAlias(() => joinedBriefBestemmeling.CtVerzendModus, () => joinedVerzendModus, JoinType.LeftOuterJoin)
.JoinAlias(() => joinedContactpersoon.CtContactpersoonType, () => joinedContactpersoonType, JoinType.LeftOuterJoin)
.JoinAlias(() => joinedContactpersoon.CtTaal, () => joinedContactpersoonTaal, JoinType.LeftOuterJoin)
.JoinAlias(() => joinedContactpersoon.TOEWIJZVERBRUIKVERANTCollection, () => joinedVerbruiksVerantw, JoinType.LeftOuterJoin)
.JoinAlias(() => joinedContactpersoon.CtProfielGroep, () => joinedProfielGroep, JoinType.LeftOuterJoin);
This is only the beginning. Here comes the part to filter the results (when needed).
if (briefType.HasValue)
{
baseQuery.Where(() => uitgaandebrief.BriefType == briefType.Value);
}
if (verzendModus.HasValue)
{
baseQuery.Where(() => joinedBriefBestemmeling.VerzendModus == verzendModus.Value);
}
if (!string.IsNullOrEmpty(binnenland) && binnenland.Trim() != "-1")
{
baseQuery.Where(() => joinedBriefBestemmeling.BinnenLand == binnenland.ToBoolean());
}
Then I got the part to select the stuff I need and translate it into the DTO (NieuwePrintopdrachtenInfo).
NieuwePrintopdrachtenInfo nieuwePrintopdrachtInfo = null;
baseQuery.SelectList(list => list
.Select(() => uitgaandebrief.UitgaandebriefId).WithAlias(() => nieuwePrintopdrachtInfo.UitgaandeBriefId)
.Select(() => uitgaandebrief.DatumInplanning).WithAlias(() => nieuwePrintopdrachtInfo.InplanningsDatum)
.Select(() => uitgaandebrief.ErrorReden).WithAlias(() => nieuwePrintopdrachtInfo.Probleem)
.Select(() => uitgaandebrief.ErrorNr).WithAlias(() => nieuwePrintopdrachtInfo.ErrorNummer)
.Select(() => uitgaandebrief.DatumCreatie).WithAlias(() => nieuwePrintopdrachtInfo.CreatieDatumBrief)
.Select(() => uitgaandebrief.DatumUpdate).WithAlias(() => nieuwePrintopdrachtInfo.DatumLaatsteWijzigingBrief)
.Select(() => uitgaandebrief.UserCreatie).WithAlias(() => nieuwePrintopdrachtInfo.BrieUserCreatie)
.Select(() => uitgaandebrief.UserUpdate).WithAlias(() => nieuwePrintopdrachtInfo.BriefUserUpdate)
.Select(() => uitgaandebrief.DatumAnnulatieElektriciteit).WithAlias(() => nieuwePrintopdrachtInfo.DatumElektriciteitGeannuleerd)
.Select(() => uitgaandebrief.DatumAnnulatieGas).WithAlias(() => nieuwePrintopdrachtInfo.DatumGasGeannuleerd)
.Select(() => joinedDossier.DossierId).WithAlias(() => nieuwePrintopdrachtInfo.DossierId)
.Select(() => joinedDossier.DossierNr).WithAlias(() => nieuwePrintopdrachtInfo.DossierNr)
.Select(() => joinedEnergieType.Omschrijving).WithAlias(() => nieuwePrintopdrachtInfo.EnergieTypeBrief)
.Select(() => joinedBriefType.Omschrijving).WithAlias(() => nieuwePrintopdrachtInfo.TypeBrief)
.Select(() => joinedVerzendModus.Omschrijving).WithAlias(() => nieuwePrintopdrachtInfo.VerzendModus)
.Select(() => joinedVerzendModus.Omschrijving).WithAlias(() => nieuwePrintopdrachtInfo.BestemmelingVerzendModus)
.Select(() => joinedBriefBestemmeling.BriefBestemmelingenId).WithAlias(() => nieuwePrintopdrachtInfo.BestemmelingId)
.Select(() => joinedBestemmelingType.Omschrijving).WithAlias(() => nieuwePrintopdrachtInfo.BestemmelingContactpersoonType)
.Select(() => joinedBriefBestemmeling.BestemmelingElektriciteit).WithAlias(() => nieuwePrintopdrachtInfo.BestemmelingElek)
.Select(() => joinedBriefBestemmeling.BestemmelingGas).WithAlias(() => nieuwePrintopdrachtInfo.BestemmelingGas)
.Select(() => joinedBriefBestemmeling.BinnenLand).WithAlias(() => nieuwePrintopdrachtInfo.BestemmelingBinnenLand)
.Select(() => joinedVerbruiksAdres.Land).WithAlias(() => nieuwePrintopdrachtInfo.LandVerbuiksadres)
.Select(Projections.Property(() => joinedContactpersoon.ContactpersoonId).As("BestemmelingContactPersoon.ContactPersoonId"))
.Select(Projections.Property(() => joinedContactpersoonType.Omschrijving).As("BestemmelingContactPersoon.TypeContactPersoon"))
.Select(Projections.Property(() => joinedContactpersoon.VoorNaam).As("BestemmelingContactPersoon.VoorNaam"))
.Select(Projections.Property(() => joinedContactpersoon.Naam).As("BestemmelingContactPersoon.Naam"))
.Select(Projections.Property(() => joinedContactpersoon.Straat).As("BestemmelingContactPersoon.Straat"))
.Select(Projections.Property(() => joinedContactpersoon.HuisNr).As("BestemmelingContactPersoon.HuisNummer"))
.Select(Projections.Property(() => joinedContactpersoon.BusNr).As("BestemmelingContactPersoon.BusNummer"))
.Select(Projections.Property(() => joinedContactpersoon.Gemeente).As("BestemmelingContactPersoon.Gemeente"))
.Select(Projections.Property(() => joinedContactpersoon.PostCode).As("BestemmelingContactPersoon.PostCode"))
.Select(Projections.Property(() => joinedContactpersoon.Appartement).As("BestemmelingContactPersoon.Appartement"))
.Select(Projections.Property(() => joinedContactpersoon.Verdieping).As("BestemmelingContactPersoon.Verdieping"))
.Select(Projections.Property(() => joinedContactpersoon.Telefoon1).As("BestemmelingContactPersoon.Telefoon1"))
.Select(Projections.Property(() => joinedContactpersoon.Telefoon2).As("BestemmelingContactPersoon.Telefoon2"))
.Select(Projections.Property(() => joinedContactpersoon.FAXNr).As("BestemmelingContactPersoon.Fax"))
.Select(Projections.Property(() => joinedContactpersoon.Email).As("BestemmelingContactPersoon.Email"))
.Select(Projections.Property(() => joinedContactpersoon.DatumCreatie).As("BestemmelingContactPersoon.DatumCreatie"))
.Select(Projections.Property(() => joinedContactpersoon.UserCreatie).As("BestemmelingContactPersoon.UserCreatie"))
.Select(Projections.Property(() => joinedContactpersoon.DatumUpdate).As("BestemmelingContactPersoon.DatumUpdate"))
.Select(Projections.Property(() => joinedContactpersoon.UserUpdate).As("BestemmelingContactPersoon.UserUpdate"))
.Select(Projections.Property(() => joinedContactpersoon.AdresBijTeWerken).As("BestemmelingContactPersoon.IsAdresBijTeWerken"))
.Select(Projections.Property(() => joinedContactpersoon.Titel).As("BestemmelingContactPersoon.Titel"))
.Select(Projections.Property(() => joinedContactpersoon.NietBesteldeBrief).As("BestemmelingContactPersoon.NietBesteldeBrief"))
.Select(Projections.Property(() => joinedContactpersoon.Land).As("BestemmelingContactPersoon.Land"))
.Select(Projections.Property(() => joinedContactpersoon.ContactpersoonAlsAanbrengerGebruikt).As("BestemmelingContactPersoon.ContactPersoonIdAlsAanbrenger"))
.Select(Projections.Property(() => joinedContactpersoon.ContactpersoonIsBetrokken).As("BestemmelingContactPersoon.ContactPersoonIsBetrokken"))
.Select(Projections.Property(() => joinedContactpersoon.NietAfgehaaldeBrief).As("BestemmelingContactPersoon.NietAfgehaaldeBrief"))
.Select(Projections.Property(() => joinedContactpersoonTaal.Omschrijving).As("BestemmelingContactPersoon.Taal"))
.Select(Projections.Property(() => joinedProfielGroep.Omschrijving).As("BestemmelingContactPersoon.IngegevenDoor"))
.Select(Projections.Property(() => joinedEan.Energietype).As("BestemmelingContactPersoon.EnergieType"))
.Select(Projections.Property(() => joinedVerbruiksVerantw.ToewijzigingVerbruiksVerantwoordelijkeId).As("BestemmelingContactPersoon.VerbruiksVerantwoordelijkeId")));
Yeah I know it is a mess. Now that you made it this far, you'll be happy to know we are almost there. This is the code I use to return the results (It is generic and uses the DeepTransform which I found here)
protected IEnumerable<TR> GetDeepTransformedPagedList<T, TR>(IQueryOver<T, T> query) where TR : class
{
PagingSettings.Count = query.Clone().Select(Projections.CountDistinct(PagingSettings.PropertyNameToCountOn)).FutureValue<int>().Value;
query = query.TransformUsing(new DeepTransformer<TR>());
if (PagingSettings.Enabled)
{
var pagedQuery = query.Skip(GetPagingStartRowIndex()).Take(PagingSettings.PageSize);
return pagedQuery.List<TR>();
}
return query.List<TR>();
}
EDIT
After the helpful post of Radim Köhler I found out that a group by won't help me with my problem. That's why I'll explain the real problem.
In code the previous query is build and extended with a Skip & Take for paging purpose. In my situation I get 50 results when executing the query.
These 50 results contain duplicates and need to be grouped by UitgaandeBriefId.
That's why the original developers wrote this code that is executed once the results are back from the DB.
ILookup<int, IEnumerable<NieuwePrintopdrachtenInfo>> groupedbrieven =
(from tbInfo in brieven
group tbInfo by tbInfo.UitgaandeBriefId into g
let UitgaandeBriefId = g.Key
let Group = g as IEnumerable<NieuwePrintopdrachtenInfo>
select new { UitgaandeBriefId, Group })
.ToLookup(result => result.UitgaandeBriefId, result => result.Group);
This code still works but results in getting only 32 results. This causes my pages to never contain 50 results. The original developer used server side paging instead of doing it on the DB so he never got this problem (performance wise this was a huge problem). That's why I refactored it so it would execute a lot faster, but this results in not getting exectly 50 results.
I guess I'll need to add a distinct then but I have no clue how I get this to work in NHibernate since I am used to work with EntityFramework.

In general, if we want to change our projection to be using GROUP BY, we have to change all "SELECT" parts to be either part of GROUP BY or SUM, MIN ...
We can do it with this kind of syntax
// firstly
// the original part from the question above
baseQuery.SelectList(list => list
...
.Select(() => joinedBriefBestemmeling.BinnenLand)
.WithAlias(() => nieuwePrintopdrachtInfo.BestemmelingBinnenLand)
.Select(() => joinedVerbruiksAdres.Land)
.WithAlias(() => nieuwePrintopdrachtInfo.LandVerbuiksadres)
.Select(Projections.Property(() => joinedContactpersoon.ContactpersoonId)
.As("BestemmelingContactPersoon.ContactPersoonId"))
.Select(Projections.Property(() => joinedContactpersoonType.Omschrijving)
.As("BestemmelingContactPersoon.TypeContactPersoon"))
...
// changed, to use GROUP BY
baseQuery.SelectList(list => list
...
.SelectGroup(() => joinedBriefBestemmeling.BinnenLand)
.WithAlias(() => nieuwePrintopdrachtInfo.BestemmelingBinnenLand)
.SelectGroup(() => joinedVerbruiksAdres.Land)
.WithAlias(() => nieuwePrintopdrachtInfo.LandVerbuiksadres)
.Select
(Projections.Alias
(Projections.GroupProperty
(Projections.Property(() => joinedContactpersoon.ContactpersoonId))
, "BestemmelingContactPersoon.ContactPersoonId"))
.Select
(Projections.Alias
(Projections.GroupProperty
(Projections.Property(() => joinedContactpersoonType.Omschrijving))
, "BestemmelingContactPersoon.TypeContactPersoon"))
...
So, now we have the GROUP BY (instead of just a SELECT) replacing the original code. But we can do more, we can introduce these (just a quick version) Extension methods (just a light version, really - but working)
public static class Extensions
{
public static NHibernate.Criterion.Lambda.QueryOverProjectionBuilder<T> GroupByProperty<T>(
this NHibernate.Criterion.Lambda.QueryOverProjectionBuilder<T> builder,
System.Linq.Expressions.Expression<Func<object>> propertyExpression,
System.Linq.Expressions.Expression<Func<object>> aliasExpression)
{
var alias = aliasExpression.ParseProperty();
var propertyProjection = Projections.Property(propertyExpression);
var groupProjection = Projections.GroupProperty(propertyProjection);
var withAliasProjection = Projections.Alias(groupProjection, alias);
builder.Select(withAliasProjection);
return builder;
}
public static string ParseProperty<TFunc>(this System.Linq.Expressions.Expression<TFunc> expression)
{
var body = expression.Body as System.Linq.Expressions.MemberExpression;
if (body.IsNull())
{
return null;
}
string propertyName = body.Member.Name;
ParseParentProperty(body.Expression as System.Linq.Expressions.MemberExpression, ref propertyName);
// change the alias.ReferenceName.PropertyName
// to just ReferenceName.PropertyName
var justAPropertyChain = propertyName.Substring(propertyName.IndexOf('.') + 1);
return justAPropertyChain;
}
static void ParseParentProperty(System.Linq.Expressions.MemberExpression expression, ref string propertyName)
{
if (expression.IsNull())
{
return;
}
// Parent.PropertyName
propertyName = expression.Member.Name + "." + propertyName;
ParseParentProperty(expression.Expression as System.Linq.Expressions.MemberExpression, ref propertyName);
}
}
And the above code could be made more readable and common, without any magic string
baseQuery.SelectList(list => list
...
.GroupByProperty(() => joinedBriefBestemmeling.BinnenLand)
,() => nieuwePrintopdrachtInfo.BestemmelingBinnenLand)
.GroupByProperty(() => joinedVerbruiksAdres.Land)
,() => nieuwePrintopdrachtInfo.LandVerbuiksadres)
.GroupByProperty(() => joinedContactpersoon.ContactpersoonId)
.() => nieuwePrintopdrachtInfo.BestemmelingContactPersoon.ContactPersoonId)
.GroupByProperty(() => joinedContactpersoonType.Omschrijving)
.() => nieuwePrintopdrachtInfo.BestemmelingContactPersoon.TypeContactPersoon)
...
NOTE IsNull() is also extension

NHibernate: Could not resolve property error

I am trying to do a query like:
var a = session.QueryOver<Site>()
.SelectList(
x => x.Select(p => p.SiteName)
.Select(p => p.SiteId).Select(p => p.RegionLocation.City))
.List<object[]>();
but I get the error
could not resolve property: RegionLocation.City of: Entities.Site
The property exists and I can retrieve it using LINQ but QueryOver does not work. What am I doing wrong ?

As far as i remember, with QueryOver, you have to join all entities in the association in order to be able to access it's properties.
This means you ought to do something like:
(notice the .JoinQueryOver)
var a = session.QueryOver<Site>()
.JoinQueryOver(s => s.RegionLocation)
.SelectList(
x => x.Select(p => p.SiteName)
.Select(p => p.SiteId)
.Select(p => p.RegionLocation.City))
.List<object[]>();
Or maybe this will work:
RegionLocation regionLocationAlias = null;
var a = session.QueryOver<Site>()
.JoinAlias(s => s.RegionLocation, () => regionLocationAlias)
.SelectList(
x => x.Select(p => p.SiteName)
.Select(p => p.SiteId)
.Select(() => regionLocationAlias.City))
.List<object[]>();
Also you might want to have a look at https://github.com/davybrion/NHibernateWorkshop/tree/master/NHibernateWorkshop
There's lots of great examples!
Specifically for your problem, have a look at: https://github.com/davybrion/NHibernateWorkshop/blob/master/NHibernateWorkshop/Querying/QueryOver/Projecting.cs