Entity Framework 7 GetType() examples

Blog_schema_and_data.sql

USE [EF7Inheritance]
GO
IF  EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[Blogs]') AND type in (N'U'))
DROP TABLE [dbo].[Blogs]
GO
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TABLE [dbo].[Blogs](
	[BlogId] [int] IDENTITY(1,1) NOT NULL,
	[Url] [nvarchar](max) NOT NULL,
	[Discriminator] [nvarchar](max) NOT NULL,
	[Password] [nvarchar](max) NULL,
	[mfaOn] [bit] NULL,
	[RssUrl] [nvarchar](max) NULL,
 CONSTRAINT [PK_Blogs] PRIMARY KEY CLUSTERED 
(
	[BlogId] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON, OPTIMIZE_FOR_SEQUENTIAL_KEY = OFF) ON [PRIMARY]
) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY]
GO
SET IDENTITY_INSERT [dbo].[Blogs] ON 
GO
INSERT [dbo].[Blogs] ([BlogId], [Url], [Discriminator], [Password], [mfaOn], [RssUrl]) VALUES (1, N'Url1', N'Blog', NULL, NULL, NULL)
GO
INSERT [dbo].[Blogs] ([BlogId], [Url], [Discriminator], [Password], [mfaOn], [RssUrl]) VALUES (2, N'Url2', N'Blog', NULL, NULL, NULL)
GO
INSERT [dbo].[Blogs] ([BlogId], [Url], [Discriminator], [Password], [mfaOn], [RssUrl]) VALUES (3, N'Url3', N'RssBlog', NULL, NULL, N'RssUrl1')
GO
INSERT [dbo].[Blogs] ([BlogId], [Url], [Discriminator], [Password], [mfaOn], [RssUrl]) VALUES (4, N'Url4', N'RssBlog', NULL, NULL, N'RssUrl2')
GO
INSERT [dbo].[Blogs] ([BlogId], [Url], [Discriminator], [Password], [mfaOn], [RssUrl]) VALUES (5, N'Url5', N'PrivateBlog', N'password1', NULL, NULL)
GO
INSERT [dbo].[Blogs] ([BlogId], [Url], [Discriminator], [Password], [mfaOn], [RssUrl]) VALUES (6, N'Url6', N'PrivateBlog', N'admin', NULL, NULL)
GO
INSERT [dbo].[Blogs] ([BlogId], [Url], [Discriminator], [Password], [mfaOn], [RssUrl]) VALUES (7, N'Url7', N'PrivateBlogWithMFA', N'pAsSwOrD', 1, NULL)
GO
INSERT [dbo].[Blogs] ([BlogId], [Url], [Discriminator], [Password], [mfaOn], [RssUrl]) VALUES (8, N'Url8', N'PrivateBlogWithMFA', N'123456', 0, NULL)
GO
SET IDENTITY_INSERT [dbo].[Blogs] OFF
GO

MyContext.cs

using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Logging;

public class MyContext : DbContext
{
    public DbSet<Blog> Blogs { get; set; }
    public DbSet<RssBlog> RssBlogs { get; set; }

    public DbSet<PrivateBlog> PrivateBlogs { get; set; }

    public DbSet<PrivateBlogWithMFA> PrivateBlogsWithMFA { get; set; }

    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
                => optionsBuilder.UseSqlServer(@"Server=(localdb)\mssqllocaldb;Database=EF7Inheritance;Trusted_Connection=True")
        .EnableSensitiveDataLogging()
            .LogTo(
                s =>  Console.WriteLine(s), LogLevel.Information);
}

public class Blog
{
    public int BlogId { get; set; }
    public string Url { get; set; }
}

public class RssBlog : Blog
{
    public string RssUrl { get; set; }
}

public class PrivateBlog : Blog
{
    public string Password { get; set; }
}

public class PrivateBlogWithMFA : PrivateBlog
{
    public bool mfaOn { get; set; }
}

Program.cs

using Microsoft.EntityFrameworkCore;
using System.Diagnostics;

namespace EF7Benchmarks
{
    internal class Program
    {
        static void Main(string[] args)
        {
            var context = new MyContext();

            //all PrivateBlogs including derived types
            //and then filter on CLIENT SIDE (bad for perf)
            Debug.WriteLine(context.PrivateBlogs.ToQueryString());


            //all PrivateBlogs excluding specific derived type(s) and descendants
            //Gets cumbersome if multiple derived types
            Debug.WriteLine(context.PrivateBlogs.
                Where(p => !(p is PrivateBlogWithMFA)).ToQueryString());


            //only PrivateBlogs specifically, not derived types
            //Does the job but syntax a little ugly. 
            Debug.WriteLine(context.PrivateBlogs.
                Where(v => EF.Property<string>(v, "Discriminator")
                    == nameof(PrivateBlog)).ToQueryString());





            //only PrivateBlogs specifically, not derived types
            Debug.WriteLine(context.PrivateBlogs.
                Where(x =>
                    x.GetType() == typeof(PrivateBlog)).ToQueryString());


            //PrivateBlog and RssBlog specifically but not dervied types
            Debug.WriteLine(context.Blogs.
                Where(x =>
                    x.GetType() == typeof(PrivateBlog) ||
                    x.GetType() == typeof(RssBlog)).ToQueryString());


            //all except PrivateBlog (will return derived types of PrivateBlog)
            Debug.WriteLine(context.Blogs.
                Where(x =>
                    x.GetType() != typeof(PrivateBlog)).ToQueryString());
        }
    }
}