I have a seemingly simple task that I am having far more trouble than I care to admit doing. I have a hierarchical table that I need to query and display the results grouped by the parent with associated children.
My current LINQ query:
var quests = Questions.Include(q => q.Question2)
.Include(q => q.Sections)
.Include(q => q.QuestionType)
.Include(q => q.AnswerOptions)
.Where(sq => sq.Sections.Any(s => s.SectionId == sectionId))
.OrderBy(q=> q.QuestionId).ThenBy(q => q.ParentQuestionId);
This produces a result set of:
What I want to produce is:
My Question is simply, how can I get the desired results using Lambda syntax.
Update based on Servys' comment.
First line is to make sure all related questions are grouped together.
Second line is to make sure parent question is first.
Third line is to order properly
.OrderBy(q => q.ParentQuestionId == null ? q.QuestionId : q.ParentQuestionId)
.ThenBy(q => q.ParentQuestionId == null ? 0 : 1)
.ThenBy(q => q.DisplayOrder);
So it seems what you're really trying to create here is a tree based structure in which, at the top level, you have all questions with no parent, and then as "child" nodes all questions that have that as a parent.
var questions = GetAllQuestions();//here is where you can put your includes, etc.
var query = questions.Where(q => q.ParentQuestionId != null)
.GroupBy(q => q.ParentQuestionId)
.Select(group => new
{
Parent = questions.First(q => q.QuestionId == group.Key),
Children = group.OrderBy(q => q.DisplayOrder),
})
.OrderBy(group => group.Parent.DisplayOrder);
.OrderBy(x => (x.ParentQuestionId==null?x.QuestionId:x.ParentQuestionId.Value));
Related
I have three classes:
OrderSet - Order (1:n) and OrderDetail (1:n)
OrderSet and Order has each a property 'Status'.
I want a receive a construct with all OrderSet with Status='open' and all regarding Orders with Status='open'.
I tried this:
var orderSet = db.OrderSet
.Where(x => x.Status == 'Open')
.Where(x => x.Order.Any(y => y.Status == 'Open'))
.Include(x => x.Order.Select(q => q.OrderDetail))
But I got all Orders, also with Status 'Closed'.
What is my fault?
Thank you in advance.
If you want to ignore OrderSets which contain any Order that doesn't have an "Open" status, you may use:
var orderSets = db.OrderSet
.Where(os => os.Status == "Open" && os.Order.All(o => o.Status == "Open")
.Include(os => os.Order.Select(o => o.OrderDetail));
If you want to include those OrderSets but only ignore the child Orders that don't meet the said condition, there's probably no way to do that without modifying the collection of OrderSets returned by the query.
If that's what you want to do, one way to achieve that would be like this:
var orderSets = db.OrderSet
.Where(os => os.Status == "Open")
.Include(os => os.Order.Select(o => o.OrderDetail)).ToList();
foreach (var orderSet in orderSets)
{
orderSet.Order.RemoveAll(o => o.Status == "Open");
}
I've a structure based of list containing other list. I need to filter the list based on the value of a property based in the deepest part of the list.
Right now I'm doing this:
queryable = queryable
.Include(x => x.Carriers)
.ThenInclude(c => c.CarrierActions)
.ThenInclude(ca => ca.Action)
.ThenInclude(ac => ac.ActionFacts);
queryable = queryable
.Where(x => x.Carriers.Any(
carriers => carriers.CarrierActions.Any(
carrieractions =>
carrieractions.Action.ActionTypeId ==
ActionTypeEnum.DosemeterCalculateDeepDose)));
I join the needed tables, then I filter them based on the ActionTypeId based 3 levels below the top list.
First off all, is it possible to do this in 1 step ( include the filtering with the joins ), second of all, the second part is not working as my list gets empty, but I'm certain that actions with that type get values.
Using .NET Core 2.0.3 btw!
To answer your first part, you can do this
queryable = queryable
.Include(x => x.Carriers)
.ThenInclude(c => c.CarrierActions)
.ThenInclude(ca => ca.Action)
.ThenInclude(ac => ac.ActionFacts)
.Where(x => x.Carriers.Any(
carriers => carriers.CarrierActions.Any(
carrieractions =>
carrieractions.Action.ActionTypeId ==
ActionTypeEnum.DosemeterCalculateDeepDose)))
To your second part, it should be working, id check your data, as this is pretty straight forward
In an effort to access child objects only through their aggregate roots, I am struggling to think of efficient ways to select the correct data. Could I rewrite the following to be more efficient/concise?
var jobReport = db.Jobs
.Where(j => j.JobReports.Any(jr => jr.ReportId == reportId))
.Select(j => j.JobReports.Single(jr => jr.ReportId == reportId))
.Single();
What you wrote would be equivalent to:
var jobReport = db.Jobs.SelectMany(j => j.JobReports)
.Single(jr => jr.ReportId == reportId);
I know that this won't work as written, but I'm struggling to see the right answer, and this non-functional code hopefully illustrates what I'm trying to achieve:
var defaults = _cilQueryContext.DefaultCharges
.Where(dc => dc.ChargingSchedule_RowId == cs.RowId);
List<DevelopmentType> devTypes =
defaults.Select(dc => dc.DevelopmentType)
.Include(d => d.DefaultCharges)
.Include(d => d.OverrideCharges.Where(oc => oc.ChargingSchedule_RowId == cs.RowId))
.Include(d => d.OverrideCharges.Select(o => o.Zone))
.ToList();
Essentially, I had presumed this required a join, but seeing as I'm trying to select a parent object containing two related types of children, I can't see what would go in the join's "select new" clause.
As far as I am aware Include does not support this type of sub-querying. Your best option is to use projection e.g.
List<DevelopmentType> devTypes =
defaults.Include(x => x.DefaultCharges)
.Include(x => x.OverrideCharges)
.Select(x => new {
DevType = x.DevelopmentType,
Zones = x.OverrideCharges.Where(oc => oc.ChargingSchedule_RowId == cs.RowId)
.Select(oc => oc.Zone).ToList()
})
.Select(x => x.DevType)
.ToList();
I'm trying to understand how this may work.
What I would have is to have all Trees from a given list of IDs that has not rotten apples.
Looks easy but I'm fresh of NHibernate, not so good in SQL and as you can see I'm stuck.
I wrote this code down here:
Tree treeitem = null;
QueryOver<Apple> qapple = QueryOver.Of<Apple>()
.Where(x => (!x.IsRotten))
.And(Restrictions.IdEq(Projections.Property<Tree>(y => y.Id)))
// Or this one...
//.And(Restrictions.EqProperty(
// Projections.Property<Apple>(y => y.Tree.Id),
// Projections.Property<Tree>(y => y.Id)))
.Select(x => x.Id);
return this.NHibernateSession.QueryOver<Tree>()
.Where(x => x.Id.IsIn(ListOfTreeId))
.WithSubquery.WhereExists<Apple>(qapple)
.SelectList(list => list
.Select(z => z.Id).WithAlias(() => treeitem.Id)
.Select(z => z.Name).WithAlias(() => treeitem.Name)
.Select(z => z.Type).WithAlias(() => critem.Type)
.TransformUsing(Transformers.AliasToBean<Tree>())
.List<T>();
And the pseudo SQL I get is something like this:
SELECT id, name, type FROM trees WHERE id IN (1, 2, 3)
AND EXIST(SELECT id FROM apples WHERE NOT rotten AND apples.idtree = apples.id)
As you can see there's a problem with the subquery that use the same table Id instead of something like that:
EXIST(SELECT id FROM apples WHERE NOT rotten AND apples.idtree = tree.id)
I'm bit lost actually. Maybe there's another way to build this up.
Any help is welcome, thanks.
Im not sure why you are using resulttransformer when the return type is the same as the query type
return NHibernateSession.QueryOver<Tree>()
.Where(t => t.Id.IsIn(ListOfTreeId))
.JoinQueryOver<Apple>(t => t.Apples)
.Where(a => !a.IsRotten)
.List();
Update: the Compiler chooses ICollection<Apple> while it really should choose Apple therefor specify the generic argument in JoinQueryOver explicitly
Update2: to get them unique
opt 1)
...
.SetResultTransformer(Transformers.DistinctRootEntity());
.List();
opt 2)
Tree treeAlias = null;
var nonRottenApples = QueryOver.Of<Apple>()
.Where(a => !a.IsRotten)
.Where(a => a.Tree.Id == treeAlias.Id)
.Select(x => x.Id); <- optional
return NHibernateSession.QueryOver(() => treeAlias)
.Where(t => t.Id.IsIn(ListOfTreeId))
.WithSubquery.WhereExists(nonRottenApples)
.List();