[c#] Ignoring a class property in Entity Framework 4.1 Code First

You can use the NotMapped attribute data annotation to instruct Code-First to exclude a particular property

public class Customer
{
    public int CustomerID { set; get; }
    public string FirstName { set; get; } 
    public string LastName{ set; get; } 
    [NotMapped]
    public int Age { set; get; }
}

[NotMapped] attribute is included in the System.ComponentModel.DataAnnotations namespace.

You can alternatively do this with Fluent API overriding OnModelCreating function in your DBContext class:

protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
   modelBuilder.Entity<Customer>().Ignore(t => t.LastName);
   base.OnModelCreating(modelBuilder);
}

http://msdn.microsoft.com/en-us/library/hh295847(v=vs.103).aspx

The version I checked is EF 4.3, which is the latest stable version available when you use NuGet.


Edit : SEP 2017

Asp.NET Core(2.0)

Data annotation

If you are using asp.net core (2.0 at the time of this writing), The [NotMapped] attribute can be used on the property level.

public class Customer
{
    public int Id { set; get; }
    public string FirstName { set; get; } 
    public string LastName { set; get; } 
    [NotMapped]
    public int FullName { set; get; }
}

Fluent API

public class SchoolContext : DbContext
{
    public SchoolContext(DbContextOptions<SchoolContext> options) : base(options)
    {
    }
    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.Entity<Customer>().Ignore(t => t.FullName);
        base.OnModelCreating(modelBuilder);
    }
    public DbSet<Customer> Customers { get; set; }
}

Examples related to c#

How can I convert this one line of ActionScript to C#? Microsoft Advertising SDK doesn't deliverer ads How to use a global array in C#? How to correctly write async method? C# - insert values from file into two arrays Uploading into folder in FTP? Are these methods thread safe? dotnet ef not found in .NET Core 3 HTTP Error 500.30 - ANCM In-Process Start Failure Best way to "push" into C# array

Examples related to .net

You must add a reference to assembly 'netstandard, Version=2.0.0.0 How to use Bootstrap 4 in ASP.NET Core No authenticationScheme was specified, and there was no DefaultChallengeScheme found with default authentification and custom authorization .net Core 2.0 - Package was restored using .NetFramework 4.6.1 instead of target framework .netCore 2.0. The package may not be fully compatible Update .NET web service to use TLS 1.2 EF Core add-migration Build Failed What is the difference between .NET Core and .NET Standard Class Library project types? Visual Studio 2017 - Could not load file or assembly 'System.Runtime, Version=4.1.0.0' or one of its dependencies Nuget connection attempt failed "Unable to load the service index for source" Token based authentication in Web API without any user interface

Examples related to entity-framework

Entity Framework Core: A second operation started on this context before a previous operation completed EF Core add-migration Build Failed Entity Framework Core add unique constraint code-first 'No database provider has been configured for this DbContext' on SignInManager.PasswordSignInAsync The instance of entity type cannot be tracked because another instance of this type with the same key is already being tracked Auto-increment on partial primary key with Entity Framework Core Working with SQL views in Entity Framework Core How can I make my string property nullable? Lazy Loading vs Eager Loading How to add/update child entities when updating a parent entity in EF

Examples related to ef-code-first

EntityType 'IdentityUserLogin' has no key defined. Define the key for this EntityType There is already an object named in the database The entity type <type> is not part of the model for the current context Entity Framework 6 Code first Default value Unique Key constraints for multiple columns in Entity Framework Entity Framework (EF) Code First Cascade Delete for One-to-Zero-or-One relationship Introducing FOREIGN KEY constraint may cause cycles or multiple cascade paths - why? How to delete and recreate from scratch an existing EF Code First database Entity Framework: One Database, Multiple DbContexts. Is this a bad idea? Ignoring a class property in Entity Framework 4.1 Code First

Examples related to entity-framework-4.1

Entity Framework Join 3 Tables How to include a child object's child object in Entity Framework 5 Ignoring a class property in Entity Framework 4.1 Code First The type or namespace name 'Entity' does not exist in the namespace 'System.Data' Validation failed for one or more entities. See 'EntityValidationErrors' property for more details StringLength vs MaxLength attributes ASP.NET MVC with Entity Framework EF Code First Entity framework code-first null foreign key How do I detach objects in Entity Framework Code First? Entity Framework Code First - two Foreign Keys from same table How Should I Declare Foreign Key Relationships Using Code First Entity Framework (4.1) in MVC3?