Entity Framework Core : Including Excluding Entities, Views, Table Valued Function in the DataModel.

We can include or exclude entity from DataModel using DBSet or OnModelCreating method like:

internal class MyContext : DbContext {

    public DbSet<Blog> Blogs { get; set; }  // Adding via DbSet

    protected override void OnModelCreating(ModelBuilder modelBuilder)  {

        modelBuilder.Entity<AuditEntry>(); // Adding via OnModelCreating; use either way.

    }

}

Note: Entities will be automatically added if declared in Navigation property.

Excluding Entity from Model:

[NotMapped]

public class BlogMetadata {

    public DateTime LoadedFromDatabase { get; set; }

}

or 

protected override void OnModelCreating(ModelBuilder modelBuilder) {

    modelBuilder.Ignore<BlogMetadata>();

}

Excluding Entity from Migration:

protected override void OnModelCreating(ModelBuilder modelBuilder) {

    modelBuilder.Entity<IdentityUser>()

        .ToTable("AspNetUsers", t => t.ExcludeFromMigrations());

}

Mapping Table Name explicitly with Entity:

[Table("blogs")]

public class Blog {

    public int BlogId { get; set; }

    public string Url { get; set; }

}

or

protected override void OnModelCreating(ModelBuilder modelBuilder) {

    modelBuilder.Entity<Blog>()

        .ToTable("blogs");

}

we can also mention schema name in Attribute/fluent API, if needed.

Mapping View with Entity

modelBuilder.Entity<Blog>().ToView("blogsView", schema: "blogging");

Note: Mapping to a view will remove the default table mapping, but the entity type can also be mapped to a table explicitly. In this case the query mapping will be used for queries and the table mapping will be used for updates.

Mapping Table Valued Function with Entity

modelBuilder.Entity<BlogWithMultiplePosts>().HasNoKey().ToFunction("BlogsWithMultiplePosts");

Note: In order to map an entity to a table-valued function the function must be parameterless.