I am using NHibernate to fetch data form SQL Server.
To get data I wrote var result = Repository.QueryOver<table_reference>().Where(c => c.Amount >100).List()
Now I want to get result filtered by foreign key reference something like
Repository.QueryOver<TaxInvoicePassing>().Where(c => c.Branch.Employee.Salary > 10000).List()
How can I achieve this?
One way is iterate for each table's record and then addrange of results
Thanks in advance
Using QueryOver, you can try this:
// declare the alias
Branch branch = null;
Employee employee = null;
Session.QueryOver<TaxInvoicePassing>() // get a queryOver of TaxInvoicePassing
.JoinAlias(t => t.Branch, () => branch) // add a join with Branch
.JoinAlias(() => branch.Employee, () => employee) // add a join with Employee
.Where(c => employee.Salary > 10000) // add where filter on employee's salary
.List();
Using Linq, it could be done like the expression you asked:
Session.Query<TaxInvoicePassing>()
.Where(c => c.Branch.Employee.Salary > 10000) // this expression will be converted on a join
.List();
I would move these queries inside the repository object instead exposing it.
Related
I am using a LinqToSql-DataSource for a GridView in this way:
wsv.wsv2DataContext db = new wsv.wsv2DataContext();
e.KeyExpression = "id";
e.QueryableSource = (from mitgliedschaft in db.mitgliedschaft
join person in db.person on mitgliedschaft.person_id equals person.id
join institution in db.institution on mitgliedschaft.verein_id equals institution.id
select new
{
vorname = person.vorname,
nachname = person.nachname,
nameVerein = institution.name,
vereinid = mitgliedschaft.verein_id,
id = mitgliedschaft.id,
verbandsMitgliedsNummer = person.verbandsMitgliedsNummer,
strasse = person.strasse,
plz = person.plz,
ort = person.ort,
geburtsdatum = person.geburtsdatum,
geschlechtid = person.geschlechtid,
statusid = mitgliedschaft.statusid,
bezirk_id = mitgliedschaft.bezirk_id,
kreis_id = mitgliedschaft.kreis_id,
person_id = mitgliedschaft.person_id.Value,
deletedFlag = mitgliedschaft.deletedFlag,
stammverein = mitgliedschaft.stammVerein,
eintrittsdatum = mitgliedschaft.eintritt
}).GroupBy(p => p.person_id).Select(p => p.First());
}
Now i want to order the Selection. At first the "stammVerein"-Column of Table "mitgliedschaft" descending AND the Column "eintritt" of Table "mitgliedschaft". I have tried several ways:
wsv.wsv2DataContext db = new wsv.wsv2DataContext();
e.KeyExpression = "id";
e.QueryableSource = (from mitgliedschaft in db.mitgliedschaft
join person in db.person on mitgliedschaft.person_id equals person.id
join institution in db.institution on mitgliedschaft.verein_id equals institution.id
orderby mitgliedschaft.stammVerein descending, mitgliedschaft.eintritt
select new
{
...
}).GroupBy(p => p.person_id).Select(p => p.First());
}
AND:
wsv.wsv2DataContext db = new wsv.wsv2DataContext();
e.KeyExpression = "id";
e.QueryableSource = (from mitgliedschaft in db.mitgliedschaft
join person in db.person on mitgliedschaft.person_id equals person.id
join institution in db.institution on mitgliedschaft.verein_id equals institution.id
select new
{
...
}).GroupBy(p => p.person_id).Select(p => p.First()).OrderByDescending(stamm => stamm.stammverein).ThenBy(eintritt => eintritt.eintrittsdatum);
}
AND:
wsv.wsv2DataContext db = new wsv.wsv2DataContext();
e.KeyExpression = "id";
e.QueryableSource = (from mitgliedschaft in db.mitgliedschaft
join person in db.person on mitgliedschaft.person_id equals person.id
join institution in db.institution on mitgliedschaft.verein_id equals institution.id
select new
{
....
}).OrderByDescending(stamm => stamm.stammverein).ThenBy(eintritt => eintritt.eintrittsdatum).GroupBy(p => p.person_id).Select(p => p.First());
But nothing of this has any Effects ! I am very new in this kind of DataSource and Linq.
Can anyone help me achieving this order ?
Items within a grouped result will not retain their order. Depending on how you want to factor in the ordering, you will need to do it after the group by, and before, and/or after your First...
To accomplish this, it will be easiest if you map the relationships in EF with navigation properties rather than substituting SQL with Linq QL (joins and such)
Using the following base query:
var query = db.mitgliedschaft
.GroupBy(m => m.Person); // Group by related entity, not ID
For instance, after the group by, you will have sets of records grouped by Person. If you want the first Person with an earliest related record:
var result = query.OrderByDescending(g => g.Key.mitgliedschafts.Max(stamm => stamm.stammverein)
.ThenBy(stamm => stamm.eintritt.eintrittsdatum)
.First();
This is taking a wild guess at your schema & entity relationships, but hopefully it will help you work out something that fits. I can only guess at what eintritt is and how it relates to your entity model.
The initial query takes just your base entities that you want to group, and groups them by the related entity. The result of that grouping will be a set of Grouped mitgliedschafts with a key being the Person. To Order those groups by the person with the most recent mitgliedschafts we use an orderby on the Key's associated mitgliedschafts using the Max value for the collection given a descending order request.
The First then gives us the first grouped collection of mitgliedschafts.
Then if you want to sort the resulting list of mitgliedschafts after getting the person with the most recent one:
var result = query.OrderByDescending(g => g.Key.mitgliedschafts.Max(stamm => stamm.stammverein)
.ThenBy(stamm => stamm.eintritt.eintrittsdatum)
.First().OrderByDescending(stamm => stamm.stammverein)
.ThenBy(stamm => stamm.eintritt.eintrittsdatum)
.ToList();
The 2nd set of OrderBy clauses apply to the selected group, or the mitgliedschafts.
To compose the desired view model, Insert a Select() to build the view model from the mitgliedschafts before the ToList().
With the navigation properties this can probably be done without resorting to a group by. On a hunch, something like this should return something similar:
var query = db.Person
.OrderByDescending(p => p.mitgliedschafts.Max(stamm => stamm.stammverien))
.ThenBy(stamm => stamm.eintritt.eintrittsdatum)
.SelectMany(p => p.mitgliedschafts)
.OrderByDescending(stamm => stamm.stammverien)
.ThenBy(stamm => stamm.eintritt.eintrittsdatum)
.Select(stamm => new { ... })
.ToList();
Anyhow, hopefully that gives you some ideas on things to try if you have the navigation properties mapped or can set those up.
I have a query like this
var errorLogs = db.ErrorLogs.Include(e => e.Inventory);
return View(await errorLogs.ToListAsync());
The Inventory Contain a field named CreatedBy
I want to add a where clause on this field how can I do it?
If it is on the Inventory table, then it should be something like the following
var errorLogs = db.ErrorLogs.Include(e => e.Inventory).Where(el => el.Inventory.CreatedBy == "Sanjoy");
I am having issues getting Nhibernate 3.3.2.4000 to generate the correct subquery used in the orderby clause as displayed below:
select *
from dbo.Person p inner join dbo.Task t on p.Task_FK = p.TaskId
order by (select p.CustomerNumber where p.IsMain=1) desc
We have two entities: Task and Person
One task can have N persons related to it. I.e Task has an IList property.
How can I make Nhibernate generate the correct subquery ? I have gotten as far as something like this with the Query API:
query = query.OrderBy(x => x.Persons.Single(t => t.CustomerNumber));
but I am unsure how I can correctly generate the where clause as displayed in the original sql query. Is this perhaps easier done using the queryover api somehow?
Any advice or guidance is most welcome.
Task task = null
Person person = null;
var subquery = QueryOver.Of<Task>()
.Where(t => t.Id == task.Id)
.JoinQueryOver(t => t.Persons, () => person)
.Where(p => p.IsMain)
.Select(() => person.CustomerNumber);
var query = session.QueryOver(() => task)
.OrderBy(Projections.SubQuery(subquery))
.FetchMany(x => x.Persons)
return query.List();
I have Entity 'Content'. Each Content has a 'Placement' property. Placement has a many-to-many relationship width 'AdType' entity (Placement has IList<\AdType> property mapped).
I need to load all Placements that are used at least in one Content and associated width specified AdType.
My DAL function looks like this:
public IList<Placement> Load(AdType adType)
{
return NHibernateSession.QueryOver<Content>()
.JoinQueryOver(content => content.Placement)
.JoinQueryOver<AdType>(placement => placement.AdTypes)
.Where(_adType => _adType.Id == adType.Id)
.Select(x => x.Placement).List<Placement>();
}
This works fine but when I look to the SQL log i see:
SELECT this_.PlacementId as y0_ FROM AdManager.dbo.[Content] this_ inner join AdManager.dbo.[Placement] placement1_ on this_.PlacementId=placement1_.PlacementId inner join AdManager.dbo.AdTypeToPlacement adtypes5_ on placement1_.PlacementId=adtypes5_.PlacementId inner join AdManager.dbo.[AdType] adtype2_ on adtypes5_.AdTypeId=adtype2_.AdTypeId WHERE adtype2_.AdTypeId = #p0
SELECT placement0_.PlacementId as Placemen1_26_0_, placement0_.Name as Name26_0_ FROM AdManager.dbo.[Placement] placement0_ WHERE placement0_.PlacementId=#p0
SELECT placement0_.PlacementId as Placemen1_26_0_, placement0_.Name as Name26_0_ FROM AdManager.dbo.[Placement] placement0_ WHERE placement0_.PlacementId=#p0
This means that NHibernate takes all placements Id in first query and then queries all fields from Placement table by Id.
My question is: Does enyone know how to modify QueryOver method to force NHibernate load data in one query?
it seems NHibernate does think there might be something in the where which maybe filters out data which is needed tro initialize the placement. You can go with a subquery:
public IList<Placement> Load(AdType adType)
{
var subquery = QueryOver.For<Content>()
.JoinQueryOver(content => content.Placement)
.JoinQueryOver<AdType>(placement => placement.AdTypes)
.Where(_adType => _adType.Id == adType.Id)
.Select(x => x.Id);
return NHibernateSession.QueryOver<Content>()
.WithSubquery.Where(content => content.Id).IsIn(subquery))
//.Fetch(x => x.Placement).Eager try with and without
.Select(x => x.Placement).List<Placement>();
}
or SQL (has the disadvantage that it just fills the new Placement but doest track it)
public IList<Placement> Load(AdType adType)
{
return NHibernateSession.CreateSQLQuery("SELECT p.Name as Name, ... FROM content c join placement p...")
.SetResultTransformer(Transformers.AliastoBean<Placement>())
.List<Placement>();
}
I would like to make this query:
Session.Linq<User>().Where(u => u.Payments.Count(p => p.Date != null) > 0);
In plain English I want to get all the users that has at least one payment with the date specified.
When I run the sample code I get a System.ArgumentException with the message:
System.ArgumentException : Could not find a matching criteria info provider to: this.Id = sub.Id
Do you know a solution to this problem?
It would also be very helpful if someone could provide the same query with the NHibernate Query by Criteria API.
I'm not sure if this will work in your particular case, but I would use the .Any() extension to clean up the linq query a bit; for example:
Session.Linq<User>().Where(u => u.Payments.Any(p => p.Date != null));
I think something like it:
Customer customerAlias = null;
criteria = CurrentSession.CreateCriteria(typeof(User), () => customerAlias);
if (searchCriteria.OrdersNumber.HasValue)
{
ICriteria paymentsCriteria = criteria.CreateCriteria<Customer>(x => x.Payments);
DetachedCriteria paymentsCount = DetachedCriteria.For<Payment>();
paymentsCount.SetProjection(Projections.RowCount());
paymentsCount.Add(SqlExpression.NotNull<Payment>(x => x.Date));
paymentsCount.Add<Payment>(x => x.Customer.Id == customerAlias.Id);
paymentsCriteria.Add(Subqueries.Gt(1, paymentsCount));
}
return criteria.List<User>();