Pomelo.entityframeworkcore.mysql: TimeSpan type does not map correctly to TIME MySQL type

Take a look at Value Conversions, specifically TimeSpanToStringConverter and TimeSpanToTicksConverter if you need a timespan greater than a month.

@mguinness Thanks for the tip. Am i correct in interpreting the timespan converter as being translated to number of ticks, that is a Long in the database?
Also if there is nothing you can do i will close the bug report.

The TimeSpan type creates a TIME typed column which has a smaller constraint than TimeSpan. Specifically TIME only goes from '-838:59:59.000000' to '838:59:59.000000' . while TimeSpan can reach 256204778:48:05.477580.

This is expected. We currently handle TimeSpan as values being smaller than 24 hours. So even new TimeSpan(1, 0, 0, 0) will not work. This mimics the behavior of SQL Server.

As @mguinness pointed out, using TimeSpanToTicksConverter is the way to go here. It can be used like this:

```c#
entity.Property(e => e.BestServedBefore)
.HasColumnType("bigint")
.HasConversion(new TimeSpanToTicksConverter());

It is equivalent to the following code:

```c#
entity.Property(e => e.BestServedBefore)
    .HasColumnType("bigint")
    .HasConversion(v => v.Ticks, v => new TimeSpan(v));

Here is a fully functional example:

```c#
using System;
using System.Diagnostics;
using System.Linq;
using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
using Microsoft.Extensions.Logging;
using Pomelo.EntityFrameworkCore.MySql.Infrastructure;
using Pomelo.EntityFrameworkCore.MySql.Storage;

namespace IssueConsoleTemplate
{
public class IceCream
{
public int IceCreamId { get; set; }
public string Name { get; set; }
public TimeSpan BestServedBefore { get; set; }
}

public class Context : DbContext
{
    public DbSet<IceCream> IceCreams { get; set; }

    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    {
        optionsBuilder
            .UseMySql(
                "server=127.0.0.1;port=3306;user=root;password=;database=Issue1046",
                b => b
                    .ServerVersion(new ServerVersion("8.0.20-mysql"))
                    .CharSetBehavior(CharSetBehavior.NeverAppend))
            .UseLoggerFactory(
                LoggerFactory.Create(
                    b => b
                        .AddConsole()
                        .AddFilter(level => level >= LogLevel.Information)))
            .EnableSensitiveDataLogging()
            .EnableDetailedErrors();
    }

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.Entity<IceCream>(
            entity =>
            {
                entity.Property(e => e.BestServedBefore)
                    .HasColumnType("bigint")
                    .HasConversion(new TimeSpanToTicksConverter());

                entity.HasData(
                    new IceCream
                    {
                        IceCreamId = 1,
                        Name = "Vanilla",
                        BestServedBefore = new TimeSpan(0, 12, 0, 0)
                    },
                    new IceCream
                    {
                        IceCreamId = 2,
                        Name = "Chocolate",
                        BestServedBefore = new TimeSpan(0, 23, 59, 59)
                    },
                    new IceCream
                    {
                        IceCreamId = 3,
                        Name = "Artificial Vanilla",

                        // This will not work out-of-the box.
                        // Usage of a converter is necessary.
                        BestServedBefore = new TimeSpan(42, 11, 0, 0)
                    }
                );
            });
    }
}

internal class Program
{
    private static void Main()
    {
        using var context = new Context();

        context.Database.EnsureDeleted();
        context.Database.EnsureCreated();

        var iceCreams = context.IceCreams
            .OrderBy(i => i.IceCreamId)
            .ToList();

        Debug.Assert(iceCreams.Count == 3);
        Debug.Assert(iceCreams[0].BestServedBefore == new TimeSpan(0, 12, 0, 0));
        Debug.Assert(iceCreams[1].BestServedBefore == new TimeSpan(0, 23, 59, 59));
        Debug.Assert(iceCreams[2].BestServedBefore == new TimeSpan(42, 11, 0, 0));
    }
}

}
```