Entity Framework Navigation Property Null


x with Entity Framework Core, Concurrency Control not working with SQLite which had a solid sample as one of the replies. In this tutorial you'll read and display related data — that is, data that the Entity Framework loads into navigation properties. Some of you may have come across a situation where you’ve created your model and found that one of the properties is null when you were expecting a value. I'm trying to create a navigation property in EF Core that would setup its reference conditionally based off the values of two properties. Sequence is a user-defined object and it generates a sequence of numeric values according to the properties with which it is created. C# / C Sharp Forums on Bytes. EF Migrations seriesUsing Entity Framework to Create a DatabaseAdding Indexes with EF MigrationsUpdating a Table with EF MigrationsIndexes in Code-Based EF MigrationsEF Migrations and a Merge ConflictPrevent EF Migrations from Creating or Changing the DatabaseEF Code First Change TrackingEF Migrations Command ReferenceEF Code First Navigation Properties and Foreign KeysUpdate-Database MSI. I am using the Entity Framework Code-First approach where I’m using ordinary C# classes to define the structure of my database. On the other, custom types such as the collection of Post objects aren't in scope by default and will be null. One of the things I really like about Entity Framework Code First is the way you can mix declarative configuration (I. Entity Framework and lazy loading Entity Framework and virtual properties. MethodKeySuffix to a string value. Quickly, we can summarize how to use these techniques in. The changes to the entity are made outside of a context. Lets discuss that next. In our previous session, we have seen that how to save data using Entity Framework in ASP. Join a community of over 2. NET classes in Entity Framework, which will then create Oracle database tables and add data to those tables. Using this generalized convention and the KeyValusFor method the AddOrUpdate can again be made generic:. The saved fields for an entity change are: The related tenant id, entity change set id, entity id, entity type name, change time and the change type. So what i wish is something like this:. The difference is that with explicit loading, the code specifies the navigation properties to be loaded. This post is about implementing an eager loading mechanism into the service. In this post I will explain how to seed database users roles dotnet core 2. In this article, we are going to create a web application using ASP. The course is a good introduction to Entity Framework 7. Solving the Detached Many-to-Many Problem with the Entity Framework the Entity Framework DbContext is instantiated by this class on construction, and implements IDisposable to ensure the. 1 you can use the Load method to do explicit loading. Built-in conventions These build an initial model based on the shape of the entity classes. Each employee has one department. Update: this feature has been postponed and will not be included in Entity Framework 5. NET Entity Framework Tutorial. You can use either Package Manager Console or dotnet CLI to execute these commands. NET Entity Framework and LINQ to Entities https:. For example, consider a girl, whose name is Emily, age is 22 and eye-color is brown. The saved fields for an entity change are: The related tenant id, entity change set id, entity id, entity type name, change time and the change type. InvalidOperationException: The cast to value type 'Int32' failed because the materialized value is null. Navigation properties are typically defined as virtual so that they can take advantage of certain Entity Framework functionality. To avoid cluttering up the object model, I don’t think there needs to be a navigation property and a foreign key property as well – the EntityReference exposes an EntityKey. Npgsql Code First Entity Framework 4. Display Records using Entity Framework in ASP. If you read my previous post on features missing in Entity Framework Core 1. And if you want to access it, you should make another call to the database which is redundant provided that you have retrieved tha necessary data for populating the Category property. Zlatko Michailov, former Entity SQL program manager at Microsoft, writes in his blog: “A well defined query against a well defined entity data model does not need JOIN. which properties have not changed, it takes the entity, and if it exists, enters the entity into the database as it’s currently populated. He had a question about how well the Entity Framework worked with other ADO. Here, I am using entity framework as data source and I have created two tables named Employee and Department. Object-relational mapping is a popular technology to map and convert between application data objects and database. We can associate a related entity by just setting their foreign key property. The difference is that with explicit loading, the code specifies the navigation properties to be loaded. Ignoring a class property in Entity Framework 4. Queries in Entity Framework Core with Explicit Loading. With the release of Entity Framework 6. In this post we will delve into the various possible code generation options for future releases of the POCO template. by using Entity Framework's Include method). Since Entity Framework works with Entity Objects, I needed some code that would take a list of classes like this and turn it into this Id Name DOB 1 Rachel Lim 6/30/1985 2 Joe Smith 3/30/1958…. Each endpoint, which participates in the relationship must return a navigation property describing the relationship. Using Self Referencing Tables With Entity Framework a top level category will have a null value for the ParentId field. > declaring navigation property in entity model and that it is a valid. In general, setting the foreign key property always trumps setting the navigation property. For example, setting the navigation property to null is the same as setting the FK to null. CRUD Operations using Stored Procedure & Entity Framework in ASP. That is, when users and addresses are pulled from the database separately, the navigation properties are populated. Navigation properties in combination with nesting sub-queries should be used instead. public class DatabaseModel : DbContext { public DatabaseModel():base() { Database. NET Entity Framework •https://entityframework. Entity Framework Bulk Inserts in. For example: Lazy loading. 3 thoughts on “ Entity Framework 7: Database Model Pluralization (Part 2/2) ” Pingback: Entity Framework 7 – Database Reverse Engineering | Empirical Thoughts. Now a window with Entity Connection string with name opens. Introduction. Here's a simple setup that would produce the error:. The Enrollments property is a navigation property. On the other hand, the StudentSubject entity contains a single reference towards the Subject entity and therefore we are populating the Subject property with the Reference method. Navigation properties in combination with nesting sub-queries should be used instead. Adding a related entity. I've been developing both classic server stuff, but also (and actually especially) more cloud-oriented stuff in the past 10 years. We can associate a related entity by just setting their foreign key property. NET Entity Framework https://entityframework. They provide an easy way to access related entities through code instead of performing some additional query to manually grab them. The model contains two entities that participate in one-to-many relationship. PatientId, it can't null it because it's marked as not null. When get the value within a trigger with SELECT SYS_CONTEXT('userenv', 'client_identifier') FROM DUAL only have the value when is a INSERT, but with UPDATE o DELETE the value is null. It should expose to the view the properties that the view wants to display (not necessarily all the views). 0 is distributed exclusively as a set of NuGet packages. If you are using one of the database providers developed as part of the Entity Framework Core project (e. Context Collections. Net Core Web API using Entity Framework Core. Entity Framework Pitfalls: Queries Over Navigation Properties When There Are Foreign Key Properties Are Ignored Thursday, September 8, 2016. The Entity Framework Conventions (or code first conventions) are default rules, which the Entity Framework uses to configure the Database. Entity Framework: Unable to load the specified metadata resource. Reverse engineers an existing database and generates Entity Framework Code First Poco classes, Configuration mappings and DbContext. and only stays those new once… What is the sense then i would like to keep entity’s framework methods as long as our new direct ExecuteReader in this post. x with Entity Framework Core, Concurrency Control not working with SQLite which had a solid sample as one of the replies. This is the first part of an n-part series on using Entity Framework 6 coming from an NHibernate background. net-mvc-4,repository-pattern. Create 2 new Product objects and add them to the Products collection of the Category. Creating an Entity Framework Data Model for an ASP. For many-to-many relationships, the Entity Framework doesn't expose the join table directly, so you must explicitly add and remove entities to and from the appropriate navigation properties. The InverseMapping option let you specify a join expression toward employee but to inverse it. net Platforms Execute raw SQL commands Foreign key property Name. In that way, your application already has a default user and role for in example logging into the application. The entities are new, but for some reason EF is attempting to insert the primary key column causing a duplicate primary key exception (attempting to insert an entity with Key. We check the version of Entity Framework in the project if the version is less than 6 then use Manage NuGet Packages for, update version of Entity Framework. 0, you’ll be please to know that a few have been addressed. Adding a related entity. State=Detached results in not filling the ICollection<> properties (foreign-keys) if set before attaching the property, or blocks clearing Id if set later on. But you can optimize the sequence with HiLo pattern. I tried to add an include but I should not need that. Aug 10, 2015 at 10:17AM it needs to be UNIQUE and NOT NULL. Entity Framework relies on every entity having a key value that it uses for tracking entities. In addition, I have unit tests using Moq and they work (the show the nav property). This post is about implementing an eager loading mechanism into the service. Entity Framework Core will create NotNull columns in the database tables for primary key properties and primitive type properties like float, int, DateTime. The following image shows a conceptual model that was created with the Entity Framework Designer. Hello all! I faced the following. Entity Framework Navigation Property Not Saving For Re-Attached Entity Jan 3, 2011 I thought I had the whole disconnected Entity Framework over WCF working well but this week I came accross a problem to do with Navigation Properties not saving when you reattach Entities and set them as modified. The reasons are architectural peculiarities of the framework, and non-optimality of the generated SQL. Configuring Entity Framework through fluent API sometimes is quite hard. Solving the Detached Many-to-Many Problem with the Entity Framework the Entity Framework DbContext is instantiated by this class on construction, and implements IDisposable to ensure the. Create the Data Model. Orders produced the equivalent result. Classes managed by EF being elements of a public API are a big problem. Even child objects will be added: So, leaving the Id values for a moment, the core of the copying code could be nothing but:. It cannot participate in associations and cannot contain navigation properties. x supports stored procedure mapping for CRUD operations. Unfortunatly, these computed properties don't work with Entity Framework out of the box. git clone cd dotnet-comic-book-gallery-model git checkout tags/v5. A specified Include path is not valid. Entity Framework set navigation property to null (C#) - Codedump. Entity Framework creates Navigation Properties for parent/child table. Learn Entity Framework Code-First in simple step-by-step tutorials. Data Annotations - Required Attribute in EF 6 & EF Core. Entity Framework can create a model based on an existing database, or create a database for you based on your model. By default, not loaded collection navigation properties are serialized as empty collections (not null). You can also clone the entity, null the properties and save. So I wrote a Get-method that does it for me: First, this is my RecursiveEntit. , by using Data Annotation attributes) with programmatic configuration for more complicated cases (I. that when called, will load the related entity's. Display Records using Entity Framework in ASP. Entity Framework core. Declaring Navigation Property in Entity Framework. One of the conventions that Code First depends on is how it implies which property is the key in each of the Code First classes. In the previous tutorial you completed the School data model. You will learn MVC 5 application with ado. NET MVC - Populating dropdown lists in Razor views using the MVVM design pattern, Entity Framework, and Ajax. Leaping ahead, I can reveal that saving data through a bypass of the context significantly minimizes the execution time. By default, the Entity Framework interprets a property that's named ID or classnameID as the primary key. cs and replace the template code with the below. In this case, the Enrollments property of a Student entity will hold all of the Enrollment entities that are related to that Student entity. Reading Related Data with the Entity Framework in an ASP. It reduces the amount of data access code developers need to write, and offers higher-performance APIs. I was hoping there was a way to have the reporting engine automatically include the other navigation properties it uses when it does the initial retrieval from the database. Net and Entity Framework 6. Nullable and the property can accept three values: true, false and null; Entity Framework support. DevForce 2010 Resource Center » DevForce development » Query » Query using property navigation » Missing objects and the null entity Missing objects and the null entity Last modified on August 15, 2012 17:20. With it, besides some bug fxes and semi-transparent improvements, came along a few goodies. Using Fluent API, you can change the corresponding column name, type, size, Null or NotNull, PrimaryKey, ForeignKey, concurrency column, etc. To make my situation clearer, here's how my model is set up:. Null columns are created for all reference data types and nullable primitive type properties like string, Nullable, float?. In EntityFramework you can query with E-SQL both building a query in string format, but also using standard method syntax, here is an example (based on NorthWind). In the following example, the post entity is inserted because it is added to the Posts property of the blog entity which was fetched from the database. One of the most frequent complaints that I hear when presenting to DBAs about Entity Framework is that it’s “slow” and that “developers should be endlessly tortured for using it”. Added NuGet support for the Entity Framework Templates. That’s why these properties should be marked as virtual – EF creates proxy class for your entity and overrides navigation properties to allow lazy-loading, so in order to resolve your problem either use eager loading (. Can be applied to a property to configure how the underlying database should generate the value for the corresponding column e. Below is the class structure I'll be working with. What if, after you load an entity, you have a reference property for another entity that is null yet you are sure that it points to a valid record? This will likely be because of one of two things: …. So even if you don't explicitly include the data for a navigation property, the property may still be populated if some or all of the related entities were previously loaded. Redis cache for PostgreSQL in Entity Framework 6 4 Database caching is a commonly used technique to improve scalability. Declaring Navigation Property in Entity Framework. NotNull property is changed to System. Net » Entity Framework » Why I do not recommend any more Entity Framework as your ORM. So now, EF will be able to figure out corresponding foreign key names. SetInitializer(new MigrateDatabaseToLatestVersion&. NET a breeze. EF will create Grade_GradeId foreign key column in the Students table if the Student entity does not contain foreignkey property for Grade. SEQUENCE was introduced in SQL Server 2012. ProductViewModel is a view model designed to be used in MVC. In EF 7, with the debugger I see that the Country is null (that's the navigation property) but I do have the countryid. But we can simplify things by creating a generic Entity Framework implementation. as I said when I get the evaluation entity from the entiry framework the parameters navigation property is null I found that when I set the Parameters property as virtual this works fine. For example, setting the navigation property to null is the same as setting the FK to null. x) framework and ASP. The following figure shows the relation between the entities. // pulling foreign key out of navigation property. Entity Framework Extensions is also available for. Lets discuss that next. Your question belongs on SO, you may be querying a SQL Server database but you are using entity-framework which does not use traditional t-sql language format. You do not HAVE to eagerly join every keyed table when performing a query, but when you need the information -- it becomes demand-driven. NET , C# , Entity Framework , Performance I wanted to write a quick entry about Entity Framework and just point out some of the errors I’ve been asked to resolve, and some of the worst uses of EF I’ve seen performance-wise. Basically in this topic we will cover how to deal with hierarchical data in entity framework. When the entity is first read, related data isn't retrieved. EmployeeID) without setting the navigation-property (Stage. See ForeignKeySmarts11 below. In this tutorial you'll read and display related data — that is, data that the Entity Framework loads into navigation properties. The examples in this article and probably in the next, will be C # used under WinForms, but - as mentioned - this choice is not going to affect a different intended use that the developer may reasonably request. NET CLI to execute entity framework core commands. How to get EF Core 3. Thankfully after some searching, I came across the GitHub issue In ASP. This is why I despise Entity Framework Posted for solidarity Because people do shit like this and now adding a new conditional join in the middle is like playing Jenga with a report. NET MVC Application Chapter5 In the previous tutorial you completed the School data model. The Required attribute can be applied to one or more properties in an entity class. Although Entity Framework tries to address the issue by allowing to choose between eager and lazy loading, I don’t think it is a good solution. As a user of such interface you never know if a navigation property is loaded and whether accessing it will result in a DB query. Leaping ahead, I can reveal that saving data through a bypass of the context significantly minimizes the execution time. But there are still workaround exists in EF Core to execute stored procedures to get the data and for CRUD operations. EF Core Console App Welcome to the Entity Framework Core Tutorial or EF Core Tutorial. For an introduction to EF take a look at our earlier tip Intro to Entity Framework with SQL Server. That will be explained in an other post. Getting Started With Entity Framework 6 Code First Using MVC 5 - Free ebook download as PDF File (. Now a window with Entity Connection string with name opens. By not specifying a property for the inverse Navigation Property, a unidirectional Many to Many relationship is created. NET has System. When I tried to set the navigation property to null, it would work only if the entity was not modified. So even if you don't explicitly include the data for a navigation property, the property may still be populated if some or all of the related entities were previously loaded. 4 -b deleting-entities Additional Learning. Thes ambitions included being able to talk seamlessly to different storage backends such as MongoDB and Redis. The Amount property is calculated, as it has no set accessor, and the logic of its value calculation is implemented in the get accessor. Which one you choose depends on your design and your needs. Furthermore, Entity Framework’s design makes it particularly friendly for PostgreSQL developers. If the DTO contains a property with the name of the collection, plus an ending of Any, Count or LongCount then it adds the LINQ method of that name. If your entity has only a reference to a list of employees and no navigation property towards the boss, it's impossible to use the JoinExpression to include the boss. Both entities have navigation properties. Entity Framework has supported optimistic concurrency since the first version. 3 and Lazy Loading Not Working for Navigation Properties Hey everyone, I'm working on a new project using Entity Framework 6. Entity Framework is a powerful and flexible object-relational mapping tool, making code-first data modeling in. Create 2 new Product objects and add them to the Products collection of the Category. I met a nice fellow at the Microsoft Code Camp in Chicago recently. Even child objects will be added: So, leaving the Id values for a moment, the core of the copying code could be nothing but:. This article will explain how to perform CRUD (Create, Read, Update and Delete) operations in Asp. NET, Entity Framework, Entity Framework Code First, ORM, Pitfalls Tags. Why is Entity Framework navigation property null? Why EF navigation property return null? The plot twist in my case is that the navigation collection properties are populated by EF, but only after I've queried DbSet properties of the dependent types in the DbContext. With this post I'd like to spell out different ways of doing it. Entity Framework Core offers a number of approaches to the creation and modification of one-to-many relationships. Invocation of the Add() method on anEmployee. Everything upto WCF level works just fine, but while returning the object, after WCF my navigation properties are setting to null. This is the first part of an n-part series on using Entity Framework 6 coming from an NHibernate background. The examples in this article and probably in the next, will be C # used under WinForms, but - as mentioned - this choice is not going to affect a different intended use that the developer may reasonably request. EF Migrations seriesUsing Entity Framework to Create a DatabaseAdding Indexes with EF MigrationsUpdating a Table with EF MigrationsIndexes in Code-Based EF MigrationsEF Migrations and a Merge ConflictPrevent EF Migrations from Creating or Changing the DatabaseEF Code First Change TrackingEF Migrations Command ReferenceEF Code First Navigation Properties and Foreign KeysUpdate-Database MSI. I'm create a few related entities and attempting to save them. The values can also be altered/joined/removed on the way through as well. com Hey There, There are actually two difference scenarios I want to accomplish. How to get EF Core 3. This post covers setting up foreign key fields. It means you have to add there entity framework context, entity mappings and implementation of repositories. INTRODUCTION I had earlier blogged about LINQ as how it has changed the face of querying the data. By the end of the article, we’ll have an operational web application that lets us create and modify test suites and add manage test cases in each test suite. NET Core + OData. You can also clone the entity, null the properties and save. Nullable and the property can accept three values: true, false and null; Entity Framework support. Relationships and navigation properties One-to-many and One-to-zero-or-one relationships can be specified in the model based on a foreign key. Navigation properties will generally exist on an Entity to represent each of the possible relationships for the specified Entity. The Enrollments property is a navigation property. State=Detached results in not filling the ICollection<> properties (foreign-keys) if set before attaching the property, or blocks clearing Id if set later on. I'm not sure if this is even possible. 1 Code First. Navigation properties. The following code is for defining entity classes (Employee and Department) and entity model. x supports stored procedure mapping for CRUD operations. ComplexType. Conventions are convenient when, for example, all the System. Lets start off by taking a look at our database context and configuration. If you find an Employer object with this ID, you retrieve the Employees associated with it. A similar extension method is included in the Entity Framework Feature CTP4 (see this article for details). These are applied automatically whenever these collections are being populated. NET Automated mechanism for accessing and storing data in the database. New Project with Entity Framework 6. When working with Entity Framework, it is important to understand how to hit the database and get the data especially to avoid the performance issues with the applications. BornInCity is the navigation property built on top of the foreign key. Working with Entity Framework Core Value Objects. In entity framework if you try to assign value to taskName that is larger than 5 characters it will fail with “Entity Validation Failed” for example:. I have implemented some code for entity framework 6. So even if you don't explicitly include the data for a navigation property, the property may still be populated if some or all of the related entities were previously loaded. NET MVC Application Chapter5 In the previous tutorial you completed the School data model. Continuous improvements every 2 months and new features released every 6 months. I'm providing a way to remove the empty properties, null values and empty arrays from the Json string. In Entity Framework Core we can have recursive entities. This method is working fine for updating non reference type values, but CurrentValues. Using this generalized convention and the KeyValusFor method the AddOrUpdate can again be made generic:. ProductViewModel is a view model designed to be used in MVC. This post is about implementing an eager loading mechanism into the service. Course is the dependent entity and has the DepartmentID foreign key property defined. Here's a simple setup that would produce the error:. Data Annotations - Required Attribute in EF 6 & EF Core. Reading this blog post helped me understand the issue a bit more. Net » Entity Framework » Why I do not recommend any more Entity Framework as your ORM. As part of this change, the Entity Framework team decided that the current EF code base would not support the ambitions of an updated ORM. [LINQ via C#] - [Entity Framework]. In Eager, …. 2 entities and the data annotations applied to those entities, to validate the data to insert. The table structure produced is the following:. Entity Framework - Fluent API - Fluent API is an advanced way of specifying model configuration that covers everything that data annotations can do in addition to some more advanced configurat. If you've worked with Entity Framework Core you might be wondering how you can map to a complex type that isn't an entity and has no DbSet in the context. In EF 6, I have an object for the navigation property. Using IdentityServer4 without Entity Framework is relatively painless. I was hoping there was a way to have the reporting engine automatically include the other navigation properties it uses when it does the initial retrieval from the database. There has recently been some confusion about what mappings are supported for collection navigation properties in EF Core. Usually, after calling SaveChanges(), EF would update the navigation property as well. Include is made to eagerly load navigation properties, meaning any property that is, in fact, another related entity. This post focuses on using the Entity Framework 4. This means your property will be ready to access : it has already been retreived. We recently released an updated version of the POCO template that works with Visual Studio 2010 RC on the Visual Studio Gallery. js with the help of the Entity Framework Core database first approach. Lately I've been developing with Entity Framework, and using dependency injection to pass the DbContext instances into my repository classes. NET web applications that use Entity Framework Code First. The following figure shows the relation between the entities. New Project with Entity Framework 6. we'll use the reference method to get the entry for the navigation property. This new logger seemed like it would be useful for logging entity framework queries. Entity Framework Core set Navigation property to null with include doesn't work Entity Framework Core Tutorial EF Core Tutorial Getting Started Model Querying Data Saving Data Providers Knowledge Base Online Examples. NET Core and Entity Framework divega changed the title EF7 doesn't lazy-load virtual navigation properties EF but the Navigation properties are null. Download Source Here Introduction. For example if there is a data context that has a dataset of entity type 'A'. Scalar properties of complex objects can be null. PostId is a shadow foreign key property created by EF. Property value must be between 1 and 12 (inclusive) This property is to be ignored by Entity Framework Database primary key Key is automatically generated by incrementing a counter Property value cannot be null / empty Property value must be formatted as an email address Declare navigation properties to be This property is a timestamp used for. A specified Include path is not valid. Internally, Entity Framework is generating a SQL to fetch all the employees associated with this employerid and return all the records as a collection of Employee entities. Use Shadow Properties. In this article, you will learn about Navigation Property with code first and navigation property in Entity Framework. The values can also be altered/joined/removed on the way through as well. net-mvc-4,repository-pattern. 2 Entity Framework 4. NET Core and Entity Framework Core (this article). 0, you'll be please to know that a few have been addressed. But unless you've been very lucky around the names in your database, you probably couldn't use Complex Types -- until Entity Framework 6, that is. Since Entity Framework works with Entity Objects, I needed some code that would take a list of classes like this and turn it into this Id Name DOB 1 Rachel Lim 6/30/1985 2 Joe Smith 3/30/1958…. After completing this tutorial we would be able to understand: How to Bind Dropdownlist using Entity Framework in ASP. NET classes in Entity Framework, which will then create Oracle database tables and add data to those tables. 5 and Visual Studio 2012/2013. One of those tweaks is the need to preemptively load related information into my business entities, mimicking the eager load from Entity Framework in navigational properties. I want to ask you a question. Entity Framework has supported optimistic concurrency since the first version. You should not use this on a set of data. There are quite a lot of tutorials showing how to create OData services using Web API OData, but these requires Entity Framework and a database server behind. Entity Framework - Fluent API - Fluent API is an advanced way of specifying model configuration that covers everything that data annotations can do in addition to some more advanced configurat. By offloading database work to other, faster stores it can also help improve the availability of the data too. The difference is that with explicit loading, the code specifies the navigation properties to be loaded. and only stays those new once… What is the sense then i would like to keep entity’s framework methods as long as our new direct ExecuteReader in this post. We check the version of Entity Framework in the project if the version is less than 6 then use Manage NuGet Packages for, update version of Entity Framework. In such a case you may write a lightweight convention instead of specifying data type for each boolean property with ColumnAttribute. The following code depicts the model representation of the database example above:. Also when implemented this i lost entity framework features whcih were stored in EmployeeService such as GetAll, Update etc. Entity Framework creates Navigation Properties for parent/child table. It is a City object reference. 0 web application using MVC, Entity Framework, and a restful Web API. Any interaction with database should be implemented in Infrastructure Layer. NET Entity Framework abstracts the relational (logical) schema of the data that is stored in a database and presents…. NET MVC 5 applications using the Entity Framework 6, Code First workflow. If your entity has only a reference to a list of employees and no navigation property towards the boss, it's impossible to use the JoinExpression to include the boss. Now I can use the method like this:.