Entity Framework Core - Example: Generated Queries

EF Core treats all SQL commands (Selects and modifications via SaveChanges) under the same logging category: Database.Command. As long as we have LogLevel.Information and LogTo enabled, they will appear in the console.

Here is an example that explicitly performs all 4 CRUD operations so we can see the log output for each one.

Complete CRUD Logging Example

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

public class Program
{
    public static void Main()
    {
        // Setup: Ensure a fresh database exists
        using (var setupContext = new AppDbContext())
        {
            setupContext.Database.EnsureDeleted();
            setupContext.Database.EnsureCreated();
        }

        using var context = new AppDbContext();

        // ==========================================
        // 1. CREATE (INSERT)
        // ==========================================
        Console.WriteLine("\n--- 1. INSERT OPERATION ---");
        var newUser = new User { Name = "John Doe", Email = "john@example.com" };
        context.Users.Add(newUser);

        // This triggers the INSERT SQL log
        context.SaveChanges(); 

        // ==========================================
        // 2. READ (SELECT)
        // ==========================================
        Console.WriteLine("\n--- 2. SELECT OPERATION ---");

        // This triggers the SELECT SQL log
        var userToUpdate = context.Users
            .Where(u => u.Email == "john@example.com")
            .FirstOrDefault();

        // ==========================================
        // 3. UPDATE
        // ==========================================
        if (userToUpdate != null)
        {
            Console.WriteLine("\n--- 3. UPDATE OPERATION ---");
            userToUpdate.Name = "Johnathan Doe"; // Modify property

            // This triggers the UPDATE SQL log
            context.SaveChanges();
        }

        // ==========================================
        // 4. DELETE
        // ==========================================
        if (userToUpdate != null)
        {
            Console.WriteLine("\n--- 4. DELETE OPERATION ---");
            context.Users.Remove(userToUpdate);

            // This triggers the DELETE SQL log
            context.SaveChanges();
        }

        Console.WriteLine("\n--- DEMO FINISHED ---");
    }
}

// ==========================================
// Entity & Context Configuration
// ==========================================

public class User
{
    public int Id { get; set; }
    public string Name { get; set; }
    public string Email { get; set; }
}

public class AppDbContext : DbContext
{
    public DbSet<User> Users { get; set; }

    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    {
        optionsBuilder
            .UseSqlServer(@"Server=(localdb)\mssqllocaldb;Database=EfCoreCrudDemo;Trusted_Connection=True;")

            // LOGGING CONFIGURATION
            // ---------------------
            // 1. Log to Console
            // 2. Filter to only show SQL Commands (removes initialization noise)
            // 3. Enable Sensitive Data to see the actual values in INSERT/UPDATE
            .LogTo(
                Console.WriteLine, 
                new[] { DbLoggerCategory.Database.Command.Name }, 
                LogLevel.Information)
            .EnableSensitiveDataLogging();
    }
}

What we will see in the Console

When we run this, we will see output similar to this (timestamps removed for clarity):

1. The INSERT Log:

--- 1. INSERT OPERATION ---
Executed DbCommand (12ms) [Parameters=[@p0='john@example.com' (Size = 4000), @p1='John Doe' (Size = 4000)], CommandType='Text', CommandTimeout='30']
SET IMPLICIT_TRANSACTIONS OFF;
SET NOCOUNT ON;
INSERT INTO [Users] ([Email], [Name])
VALUES (@p0, @p1);
SELECT [Id]
FROM [Users]
WHERE @@ROWCOUNT = 1 AND [Id] = scope_identity();

2. The SELECT Log:

--- 2. SELECT OPERATION ---
Executed DbCommand (2ms) [Parameters=[@__targetEmail_0='john@example.com' (Size = 4000)], CommandType='Text', CommandTimeout='30']
SELECT TOP(1) [u].[Id], [u].[Email], [u].[Name]
FROM [Users] AS [u]
WHERE [u].[Email] = @__targetEmail_0

3. The UPDATE Log:

--- 3. UPDATE OPERATION ---
Executed DbCommand (8ms) [Parameters=[@p1='1', @p0='Johnathan Doe' (Size = 4000)], CommandType='Text', CommandTimeout='30']
SET IMPLICIT_TRANSACTIONS OFF;
SET NOCOUNT ON;
UPDATE [Users] SET [Name] = @p0
OUTPUT 1
WHERE [Id] = @p1;

4. The DELETE Log:

--- 4. DELETE OPERATION ---
Executed DbCommand (3ms) [Parameters=[@p0='1'], CommandType='Text', CommandTimeout='30']
SET IMPLICIT_TRANSACTIONS OFF;
SET NOCOUNT ON;
DELETE FROM [Users]
OUTPUT 1
WHERE [Id] = @p0;