SQLite Example in C# that Creates Rows with NewId and Random Data via DbContext

Program.cs

using System.ComponentModel;
using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;

using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.ChangeTracking;
using Microsoft.EntityFrameworkCore.Metadata;

using MassTransit;

Console.WriteLine($"Inserting {args[0]} records");

JoyDbContext joyDbContext = new();

joyDbContext.Database.EnsureCreated();

joyDbContext.Database.ExecuteSqlRaw("PRAGMA journal_mode=WAL;");

Random random = new();

int start = (int)Math.Max(1, joyDbContext.Joy
    .Select(v => v.JoyId).DefaultIfEmpty().Max());

foreach (int idx in Enumerable.Range(start, Int32.Parse(args[0])))
{
    joyDbContext.Add(new JoyEntity
    {
        Uuid = NewId.Next().ToString(),
        ExampleData = Convert.ToBase64String(
            BitConverter.GetBytes(random.Next(Int32.MaxValue)))
    });

    if (idx % 300 == 0) {
        Console.WriteLine($"{DateTime.Now.ToString("s")}: {idx}");

        joyDbContext.SaveChangesAsync();

        joyDbContext.ChangeTracker.Clear();
    }
}

[Index(nameof(Uuid), IsUnique = true)]
public class JoyEntity
{
    [Key]
    public long JoyId { get; set; }

    [Required]
    public string Uuid { get; set; }

    [Required]
    public string ExampleData { get; set; }

    [DefaultValue(typeof(DateTime), "")]        
    public DateTime Updated { get; set; }

    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public DateTime Inserted { get; set; } = DateTime.UtcNow;
}

public class JoyDbContext : DbContext
{
    public DbSet<JoyEntity> Joy { get; set; }

    public JoyDbContext()
    {
    }

    public JoyDbContext(DbContextOptions options) : base(options)
    {
    }

    protected override void OnConfiguring(DbContextOptionsBuilder options)
    {
        options
            .UseSqlite($"Data Source=joy.sqlite");
    }

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        base.OnModelCreating(modelBuilder);

        foreach (IMutableForeignKey fk in modelBuilder.Model.GetEntityTypes().SelectMany(e => e.GetForeignKeys()))
        {
            fk.DeleteBehavior = DeleteBehavior.Restrict;
        }
    }

    public override Task<int> SaveChangesAsync(CancellationToken cancellationToken = new CancellationToken())
    {
        IEnumerable<EntityEntry> entries = ChangeTracker
            .Entries()
            .Where(e => e.State == EntityState.Modified);

        foreach (EntityEntry entityEntry in entries)
        {
            entityEntry.Entity.GetType().GetProperty("Updated")?.SetValue(entityEntry.Entity, DateTime.UtcNow);
        }

        return base.SaveChangesAsync(cancellationToken);
    }

    public override int SaveChanges()
    {
        IEnumerable<EntityEntry> entries = ChangeTracker
            .Entries()
            .Where(e => e.State == EntityState.Modified);

        foreach (EntityEntry entityEntry in entries)
        {
            entityEntry.Entity.GetType().GetProperty("Updated")?.SetValue(entityEntry.Entity, DateTime.UtcNow);
        }

        return base.SaveChanges();
    }
}

SQLiteLargeTest.csproj

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>net6.0</TargetFramework>
    <ImplicitUsings>enable</ImplicitUsings>
    <Nullable>enable</Nullable>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="Microsoft.EntityFrameworkCore.Sqlite" Version="6.0.1" />
    <PackageReference Include="NewId" Version="3.0.3" />
  </ItemGroup>

</Project>

summary.txt

$ time dotnet run 15000000
...
dotnet run 15000000  965.22s user 753.46s system 70% cpu 40:33.50 total
$ ls -lFa -h joy.sqlite 
-rw-r--r--  1 bpm  staff   2.2G Dec 22 13:44 joy.sqlite
$ sqlite3 joy.sqlite <<< 'select count(JoyId) from Joy;'
15000000