EF Core 6.0 release and breaking change notes

[roji]

Includes documentation on the timestamp handling changes.

Closes #115

@vonzshik @NinoFloris this is the EF Core side of things - I will work on the ADO.NET notes later today.

(don't forget these are docs so we can always improve them later - we should merge these soon since that needs to happen before we release rc1)

[Arth-OOZEE]

getting error while saving datetime column to database (postgresql)

[Tieantono]

getting error while saving datetime column to database (postgresql)

Check this documentation: https://www.npgsql.org/efcore/release-notes/6.0.html#nodatime-changes

Example codes:

var currentDate = DateTimeOffset.UtcNow.DateTime;
// Specify the DateTimeKind here.
currentDate = DateTime.SpecifyKind(updatedAt, DateTimeKind.Utc);

// Your entity object, let's say you have a table named `employee`.
var employee = new Employee
{
    Id = Guid.NewGuid(),
    // Your `created_at` column with data type timestamp with time zone / timestamptz.
    CreatedAt = currentDate
}
_dbContext.Employees.Add(employee);
_dbContext.SaveChanges();

[roji]

@Tieantono please open a new issue with a runnable code sample rather than posting on this PR.

FYI here's a minimal code sample which shows the above working with 6.0.

Code sample

await using var ctx = new EmployeeContext();
await ctx.Database.EnsureDeletedAsync();
await ctx.Database.EnsureCreatedAsync();

var currentDate = DateTime.UtcNow;

// Your entity object, let's say you have a table named `employee`.
var employee = new Employee
{
    Id = Guid.NewGuid(),
    // Your `created_at` column with data type timestamp with time zone / timestamptz.
    CreatedAt = currentDate
};
ctx.Employees.Add(employee);
ctx.SaveChanges();

public class EmployeeContext : DbContext
{
    public DbSet<Employee> Employees { get; set; }

    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        => optionsBuilder
            .UseNpgsql(@"Host=localhost;Username=test;Password=test")
            .LogTo(Console.WriteLine, LogLevel.Information)
            .EnableSensitiveDataLogging();
}

public class Employee
{
    public Guid Id { get; set; }
    public string Name { get; set; }
    public DateTime CreatedAt { get; set; }
}

[Tieantono]

@roji Hi, I was just giving @Arth-OOZEE an example, not asking for a solution, but your example simpler than mine, I forgot that you could DateTime.UtcNow to obtain the DateTime object with UTC value, thanks.

[roji]

@Tieantono oh sorry, I missed that - thanks for helping out! @Arth-OOZEE please open a new issue if you continue to run into trouble.