EF Code 如何应对高并发

string _currOwner = Console.ReadLine();//当前用户
using var ctx = new MyDBContext();
var cop = ctx.Coupons.Single(x => x.Id == 2);
if (!string.IsNullOrEmpty(cop.Owner))
{   Console.WriteLine($"券被抢了");
}
else
{   cop.Owner = _currOwner;   Thread.Sleep(5000);   ctx.SaveChanges();   Console.WriteLine($"恭喜{_currOwner}抢到券{cop.Id}了");
}
Console.ReadLine();

string _currOwner = Console.ReadLine();//当前用户
using var ctx = new MyDBContext();
using var tx = ctx.Database.BeginTransaction();
FormattableString sql = $@"select * from Coupons with(updlock) where id=2";
var cop = ctx.Coupons.FromSqlInterpolated(sql).Single();
if (!string.IsNullOrEmpty(cop.Owner))
{   Console.WriteLine($"券被抢了");
}
else
{   cop.Owner = _currOwner;   Thread.Sleep(5000);   ctx.SaveChanges();   Console.WriteLine($"恭喜{_currOwner}抢到券{cop.Id}了");
}
tx.Commit();
Console.ReadLine();

            builder.Property(x => x.Owner).IsConcurrencyToken();

string _currOwner = Console.ReadLine();//当前用户
using var ctx = new MyDBContext();
var cop = ctx.Coupons.Single(x => x.Id == 2);
if (!string.IsNullOrEmpty(cop.Owner))
{   Console.WriteLine($"券被抢了");
}
else
{   Thread.Sleep(5000);   try   {       cop.Owner = _currOwner;       await ctx.SaveChangesAsync();       Console.WriteLine($"恭喜{_currOwner}抢到券{cop.Id}了");   }   catch (DbUpdateConcurrencyException ex)   {       var entry = ex.Entries.First();       var dbValues = entry.GetDatabaseValues();       var newOwner = dbValues.GetValue<string>(nameof(Coupon.Owner));       Console.WriteLine($"并发冲突，{newOwner}已经抢到该券了");   }
}

    public class Coupon   {       public int Id { get; set; }       public string Name { get; set; }       public string? Description { get; set; }       public string? Owner { get; set; }       public byte[] RowVersion { get; set; } #迁移到数据库，类型为rowversion，当数据更新时，版本会自动递增   }

CREATE TABLE [dbo].[Coupons] (   [Id]          INT            IDENTITY (1, 1) NOT NULL,   [Name]        NVARCHAR (MAX) NOT NULL,   [Description] NVARCHAR (MAX) NULL,   [Owner]       NVARCHAR (MAX) NULL,   [RowVersion]  ROWVERSION     NOT NULL,   CONSTRAINT [PK_Coupons] PRIMARY KEY CLUSTERED ([Id] ASC)
);

            builder.Property(x => x.RowVersion).IsRowVersion();