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Entity Framework 5 Eager Loading. How queries are built?
That's normal. In your simple case (1 include) you see EF doing the real query as a subquery, then it selects over it and applies ordering. If you try including more includes in a single query, you will see the behaviour change, as it will start to do a single query per entity and then "union all" the queries together, and finally select over the result. In my experience eager loading in EF leads almost always in a drop of performance, so I'd recommend avoiding it unless you have specific needs and you have deeply considered the performance impact.

Categories : C#

Missing Information When Eager Loading With Entity Framework
Try to remove this mapping line from PriceGridColumnMap: HasRequired(x => x.PriceGridRow); which basically means that the relationship the PriceGridRow navigation property belongs to does not have an inverse navigation property. It is a shortcut for: HasRequired(x => x.PriceGridRow) .WithMany()... But this is in contradiction with the mapping in PriceGridRowMap: HasMany(x => x.PriceGridColumns) .WithRequired(x => x.PriceGridRow)... which says that the PriceGridRow navigation property does have an inverse navigation property, namely PriceGridColumns.

Categories : Entity Framework

Eager Loading Complex Query with Entity Framework 5
In my opinion when you are issuing a complex query that joins across twenty tables you might want to start of with inspecting the database itself Here are some guidelines (some points are pertinent to SQL Server, which I have taken the liberty to assume is the database you are using) Check the query execution plan on the raw SQL - If it is time consuming to reproduce the entire EF code in SQL just maybe parts of it - for instance the ServiceTrips, ServiceAssignments and DeliveryOrder tables. This will give you an idea of the bottlenecks with regards to indexes etc Inspect if, because of the size of the data, network latency is the bottleneck and not the query itself Consider using indexed views which might improve your performance Architecture - To speed up such complex queries use c

Categories : C#

Entity Framework 4.3.1 Eager Loading Multiple Levels of Child Objects With Filter
You can't load filtered data with Entity Framework. Navigation properties either contain all related entities, or none of them. Consider to do manual join and return anonymous objects with not deleted options.

Categories : Entity Framework

Entity Framework Eager Loading Table-Per-Type Inheritance derived class
I don't see why ... var list = context.Trainings.Include(t => t.Persons) .Where(t => t.Name == someName) .ToList(); ... shouldn't work. EF should populate the Persons list with concrete Student and Instructor entities. You neither have a "one-to-zero-or-one relationship" nor is your navigation property (Training.Persons) "on the derived class". So, I think the mentioned limitation does not apply to your model and query.

Categories : Entity Framework

Entity framework two-way relationship not loading includes
Are you sure that you want to put ForeignKey on RowId, I think you may want to define some relationship like this public class Type { [Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)] public Guid RowId { get; set; } public string TypeName { get; set; } public int ChargeId { get; set; } [ForeignKey("ChargeId")] public virtual Charge Charge { get; set; } }

Categories : Entity Framework

Entity Framework: One-to-many relationship issue with seeding. EF attempting to cast object to collection
Relation between Product and Market as you declared it is not One To Many. You have ForeignKey attribute on the Market property using "Id" property that is key in the Product class. That makes it One-To-One, meaning both Market and Product should have the same Id. You need additional "MarketID" property in the Product and use that property as the ForeignKey. Or don't use the ForeingKey attribute at all

Categories : C#

Use Entity Framework to request parent-child object collection when no explicit relationship exists
There is no better way to do this than your second approach. This is because Entity Framework is only able to load collections that have a foreign key relationship to the PK of the parent. There is no support for associations to unique indexes yet. Likewise, the process you're referring to, relationship fixup, can only work when the association is mapped. But in your case it can't be mapped, so EF can't populate the collections itself.

Categories : C#

Laravel 4 Eager Loading in Many to Many Relationship
You should try: $facilities = Facility::with('photos')->get(); Remember, the argument you are passing to with() is the method, not the model, so if you have another method in the model, say: location(), you'll call: $facilities = Facility::with(['photos', 'location'])->get();

Categories : PHP

Eager loading laravel 3 deep relationship
Using an enclosure method should work... // Like this... Agent::with(array('city' => function($query){ $query->with('state'); }))->find($id); // Also, I would keep my model relationship methods lowercase class City extends Eloquent { public static $table = 'city'; //public function State() public function state() // like this { return $this->belongs_to('State','state_id'); } } Scroll down to "Constraining Eager Loads" at the below link to see enclosure methods in use https://tower.la.utexas.edu/index.php/docs/database/eloquent#eager

Categories : PHP

Eloquent ORM Eager-loading Distinct Records in Many to Many Relationship
Retrieving unique subscribers through join I'll try my best to explain it using Lists instead of Adressbook, because I couldn't really understand your model and that may introduce further confusion. If I understood your comments correctly, you are trying to retrieve all unique subscribers that have associations with lists of id IN listarray. In that case, Eager Loading is not the proper way of doing that. Eager loading serves the purpose of pre-loading associations for a model, in order to use them later on. In your case, you are not retrieving Lists and their Subscribers, but rather the unique Subscribers themselves. $lists = Input::get('listsarray'); $subscribers = Subscriber::join('list_subscriber', 'list_subscriber.subscriber_id', '=', 'subscribers.id') ->whereIn('list_subsc

Categories : Laravel

SQLAlchemy eager loading collection size / count
# alias comments table because it will appear twice in query comments = aliased(Comment) result = (session.query(Comment, func.count(comments.id)) .filter(Comment.wall==wall) .join(Person) # we need to join person table explicitly .join(comments) # to reach comments table again in another join .group_by(Comment.id) # populates relationship using explicitly joined table .options(contains_eager(Comment.commenter)) .all())

Categories : Python

NHibernate - Nested Eager loading is being ignored
It should work with something like this: QueryOver<Parent>() .Where(c => c.Id == id) .Inner.JoinQueryOver(p => p.Children) .Inner.JoinQueryOver(c => c.GrandChild) .Inner.JoinQueryOver(g => g.GreatGrandChildren) .Fetch(p => p.Children).Eager .Fetch(p => p.Children.GrandChild).Eager .Fetch(p => p.Children.GrandChild.GreatGrandChildren).Eager .TransformUsing(Transformers.DistinctRootEntity) Fetch.Eager tells NH to load those nested collection within one request, TransformUsing basically tells it you want a distinct on Parent

Categories : C#

Can I use ActiveRecord::Associations::Preloader / eager loading to load a has_one relationship with dynamic conditions?
The problem is that self isn't your object in the has_many, it's the association proxy. If you want the profile object that is referenced in the association, it should be owner (though this is slightly dependent on the version of Rails you're running -- check the documentation for Rails association extensions for more details).

Categories : Ruby On Rails

Nested eager loading with attribute accessors
Have you tried this? data = current_country.manufacturers.to_json :include => {:cars => {:methods => [:attr_accessor_1, :attr_accessor_1], :comfort_levels => {}}}

Categories : Ruby On Rails

Rails 3 eager loading of deep nested association
Are you not able to use the standard eager loading syntax? @activities = PublicActivity::Activity.order("id desc").includes(:owner, :trackable => {:post => :content})

Categories : Ruby On Rails

How can I use eager loading with scope in complicated nested association?
Shouldn't be particularly complicated, just .includes all the bits you want to eager load .. @community.codes.recent.includes(user: :profile) Also, are a Community's codes always equal to that of all of it's Users? If so, you should be using a has_many :codes, through: :users association on Community.

Categories : Ruby On Rails

Delete entity with non-nullable foreign key relationship entity framework 5 POCO
Okay, so the problem here ended up being that the items that I ended up trying to delete (or modify/attach to the context) were not the proxies that were pulled from the original query to the database. So, the entity framework was complaining because it though I was trying to modify the primary key of an entity it was already tracking with a new entities value (the exception, although correct, was misleading). The solution here is to make certain that I am not trying to attach or update with a non-proxy entity when the context has already started tracking a proxy version of the same entity.

Categories : C#

Entity Framework: Trying to query an entity with a foreign key relationship
Since the mapping User-Group is n - 1 the mapping should be: var entity = modelBuilder.Entity<User>(); entity.HasRequired(a => a.Group) // user has one Group .WithMany() // Group has many Users .Map( a => a.MapKey("GroupId")); EF created the Group_Id column itself for the 1-n association it inferred from your class model, while GroupId was added because of the 1:1 association you mapped yourself.

Categories : C#

How to eager load an association after eager loading on the parent?
I'm posting this an answer to make sure that it's clear it's been resolved. Once I'm capable I will accept this as the correct answer. Baldrick's comment got me to thinking about how exactly I was filtering out activities for the user so that I only had the activities logged to the active organization. I was performing: user.activities.where("organization_id = ?", org.id) Which would force a query every time regardless of what I've done. So I changed it to: user.activities.select { |o| o.id == org.id } Which now performs what I've wanted (after @Baldrick's recommendation as well).

Categories : Ruby On Rails

Entity Framework 1 to 0 relationship
Yes, but the porpouse of attach is not adding the element to the duplicata bu to get into the context a detached entity. If you want to create a new duplicata just create a new one. Like in // just for testing NO magic numbers! var pagamentoId = 1; var duplicata = new Duplicata(); duplicata.PAGAMENTO_ID = pagamentoId; duplicata.VALOR = 1000; duplicata.CLIENTE_ID = 23; // add the rest of properties // then... context.AddObject("Duplicatas", duplicata); context.SaveChanges(); Note I used "Duplicatas" in the addobject as I assumed that is your name for the Duplicata set (set means it's a collection of Duplicata and you set that name in the EDMX file). By setting the pagamento_id to the value you want it automatically generates the relationship between both entities

Categories : C#

Entity Framework: Many-to-many relationship with self
Turned out to be simple: HasMany(x => x.Referals).WithMany(x => x.Encapsulated).Map(c => { c.ToTable("DataFieldJoin"); c.MapLeftKey("RefId"); c.MapRightKey("EncapId"); });

Categories : C#

Entity Framework Code-First One-To-One Relationship
If you are going for code first and want to have both Customer And CustomerSettings classes, but only a single table for both, as your post suggests , I would use complex types. see a good example here: http://weblogs.asp.net/manavi/archive/2010/12/11/entity-association-mapping-with-code-first-part-1-one-to-one-associations.aspx So , your object model should look like this (I've not tested it): public class Customer { public Customer() { CustomerSetting= new CustomerSetting(); } public int CustomerId { get; set; } public int Name { get; set; } public CustomerSetting CustomerSetting { get; set; } } [ComplexType] public class CustomerSetting { public int CustomerId { get; set; } public int Setting1 { get; set; } public int Setting2 { get; se

Categories : Entity Framework

One-to-one relationship in CF Entity Framework using mapping
Just looked at it again, do you need to add HasKey to UserMap so it knows which one is the key otherwise you could do the following :- Are you able to change UserProfile to inherit from User and then add this to your OnModelCreating method modelBuilder.Entity().ToTable("UserProfile"); this will create your one to one relationship on the database. I had to do this with my current model to get one to one otherwise if you do not specify the ToTable part it will lump them into one table with a Discriminator column cheers Mark

Categories : C#

entity framework 5, delete one to many relationship?
Sadly, there is (currently) no batch support in Entity Framework, so you're stuck foreach-ing through multiple properties. You might want to look at the EntityFramework.Extended project, which adds various batch operations to tidy up code like this (as well as improving performance). If you're sure you'll always want to delete the related B's when an A is deleted, then configure this relationship to use "on delete cascade" behaviour. What that means is that when a parent A is deleted, all of its child B's are automatically deleted as well. How to do that depends on how you've created the database. If you're using Code First, it'll be something like this: public class MyContext : DbContext { public DbSet<A> As { get; set; } public DbSet<B> Bs { get; set; } protect

Categories : Entity Framework

Where() method and many to many relationship with the entity framework
Suppose you have Videos defined in the dbContext as db, try this var result = db.Videos.Where(x => x.Name.Equals("Apple")) .Where(x => x.Tags.Count(y => y.tagName.Equals("Green")) == 1);

Categories : Entity Framework

Entity Framework 1 to 1 relationship using code first. how?
This occurs in CodeFirst because of the virtual keyword. In effect, you are creating a relationship where creating one item requires the creation of the other. however, the virtual keyword allows lazy instantiation, which means that creating an object of one type doesn't automatically create the other type, allowing the Id on the foreign item to be null. This implies a 0..1 relationship, but since each side is virtual, what you get is a 0..0 which isn't allowed. There are 2 methods which you can use to remedy the situation. remove the virtual option from either one side or both sides of the navigation properties, allowing for a 0..1 or a 1..1 map. explicitly add a property for the Foreign key from the other entity on each object. i.e. on class Region add a property for FactoryId and

Categories : Entity Framework

0..1 to 0..1 relationship in entity-framework by data annotation
You can do something like this: public class Foo { [Key] public int FooId { get; set; } public virtual Bar Bar { get; set; } } public class Bar { [Key] public int BarId { get; set; } public virtual Foo Foo { get; set; } } Hope it helps! Good Luck :)

Categories : Entity Framework

One to one optional relationship using Entity Framework Code First
Try adding the ForeignKey attribute to the LoyaltyUserDetail property: public class PIIUser { ... public int? LoyaltyUserDetailId { get; set; } [ForeignKey("LoyaltyUserDetailId")] public LoyaltyUserDetail LoyaltyUserDetail { get; set; } ... } And the PIIUser property: public class LoyaltyUserDetail { ... public int PIIUserId { get; set; } [ForeignKey("PIIUserId")] public PIIUser PIIUser { get; set; } ... }

Categories : C#

Defining one to zero relationship in entity framework code first
Dummy mistake (sad trombone sound here) ! The Store class have a lot of properties and I found that the StoreType property has been defined twice with 2 differents names ... I hope it will help someone else if you're stuck with the same issue. Thanks

Categories : C#

entity framework code first double many to many relationship
I think you can achieve that using two relation tables, one for the Debtors and one for the Creditors. modelBuilder.Entity<Customer>().HasMany(c => c.Debtors).WithMany(d => d.Debtors).Map(m => m.MapLeftKey("CustomerId").MapRightKey("DossierId").ToTable("DebtorCustomerDossierRel")); modelBuilder.Entity<Customer>().HasMany(c => c.Creditors).WithMany(d => d.Creditors).Map(m => m.MapLeftKey("CustomerId").MapRightKey("DossierId").ToTable("CreditorCustomerDossierRel")); I haven't tried this code, but it should work pretty close to that. This would be in your DbContext.OnModelCreating method (for that are new to Code First).

Categories : Entity Framework

Entity Framework "The relationship could not be changed" with simple one-to-many
Your comment in source code: public int UserId { get; set; } // user that created the video, unrelated Unrelated? Most likely this is the foreign key for the one-to-many relationship in question because mapping conventions will detect it as the foreign key since it has the same name as the primary key property UserId in UserProfile. And because the property has a non-nullable type int EF will detect the relationship as required which means that no video can exist without having a user who upvoted it. This is what the exception says when you remove the video from the UpvotedVideos collection which means that the relationship to the current user who upvoted the video is removed. You can do this but because every video must have a user who upvoted it you must assign the video either to a

Categories : C#

Create one to one relationship by using entity framework database first
Creating a 1:1 relationship is not that tricky and certainly not impossible, although it is not a particularly common requirement and in this case I can't see why you would want it? If people are saying this then you are talking to the wrong people. Anyhow using SQL queries as you seem to be is not to do with EF, you are just working directly with the database, In the first CREATE you are trying to add the constraint but you haven't created the other table yet... As you mentioned in your question. I think you need to create both tables first and then add the constraint with ALTER TABLE. Additionally searching SO for questions about 1:1 turns up quite a lot so I suggest you do that. EDIT: So using a database project (I only have VS Express so I don't have those) you want to create a "1

Categories : Entity Framework

How to query many-to-many relationship with 'AND' condition using LINQ and Entity Framework
I'd try this (For all given ids there is any (= at least one) feature that has this given id): var establishments = context.Establishments .Where(e => featureIds.All(fid => e.Features.Any(f => f.FeatureId == fid))) .ToList(); (featureIds is an IEnumerable<int> with the Ids being searched for.)

Categories : C#

Entity Framework (EF) Code First Cascade Delete for One-to-Zero-or-One relationship
You will have to use the fluent API to do this. Try adding the below to your DB Context protected override void OnModelCreating(DbModelBuilder modelBuilder) { modelBuilder.Entity<User>() .HasOptional(a => a.UserDetail) .WithOptionalDependent() .WillCascadeOnDelete(true); }

Categories : C#

Self-referencing relationship in Entity Framework with child includes
One way would be to take advantage of Entity Framework's Lazy Loading features. You would need to alter your object slightly by adding to virtual keyword to your navigation properties so they meet EF requirements for creating POCO proxies: public class Activity { public int Id {get;set;} public String Name {get;set;} public virtual IList<Document> Documents {get;set;} public virtual IList<Activity> ChildActivities {get;set;} } You should now be able to access the Documents of your ChildActivities without having to explicitly load them (either via Eager/Explicit loading).

Categories : Linq

Problems creating a Foreign-Key relationship on Entity Framework
There is a conflict between your foreign key property in class Dettaglio... public virtual int IDTEST { get; set; } ...which has a non-nullable type (int) and therefore cannot be optional and your mapping... this.HasOptional(t => t.TEST_TABLE) //... ...where you want the relationship to be optional. If you indeed want an optional relationship use a nullable FK property: public virtual int? IDTEST { get; set; } Otherwise you must use HasRequired for a required relationship with a non-nullable FK property.

Categories : C#

mvc entity framework many-to-many relationship of entities from multiple database
Short answer is you can't. EF can only deal with one context (and even schema) at a time. However, you can: Create a service layer (with its own set of entities) and place the joining logic there. And now the service entities become a collage of information pulled from multiple locations. Create table-valued functions that call pull information from both locations and return the joined information in s format that one EF context would encompass in a single object. Use something like Dapper.net and use synonyms in the database and query it to your own model.

Categories : Asp Net Mvc

Entity Framework - Updating relationship by changing foreign key
Try something like this : using (TestDbContext context = new TestDbContext()) { foreach (Person person in People) { if (!(context.People.Any(p => p.ID == person.ID))) context.People.Add(person); else { context.People.Attach(person); context.Entry<Person>(person).State = System.Data.EntityState.Modified; } context.SaveChanges(); } foreach (Car caar in Cars) { if (!(context.Cars.Any(c => c.ID == caar.ID))) context.Cars.Add(caar); else

Categories : C#

Keep list of foreign keys in many-to-many Entity Framework relationship
Would some simple getters suffice? public IEnumerable<int> ArticlesId { get { return this.Articles.Select(a => a.Id); } } public IEnumerable<int> CompaniesId { get { return this.Companies.Select(c => c.Id); } } This would cover many use cases. Of course since this isn't a virtual association property, you lose some of the flexibility of using these properties in actual Linq-to-Entities queries.

Categories : C#



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