valueobjects | PHP library/collection of classes / | Functional Programming library

I was using Javers for mongoDB document versioning with springboot. It provides essential functionalities for versioning such as separate history collection called jv_snapshots, changed field list in Entity or ValueObject model for their versions. But I found an issue relevant to valueObjects, but not entities. As you know, the difference between entity and valueObjects is the unique id that identifies the entity, but valueObjects don't have such Id to identify their versions. Refer the following examples as I observed this issue in my use case.

Let's take the following Entity and valueObject models for versioning.

Invoice.java

Hi good people of Internet :)
I am trying to use EF Core 5 entities as domain entities in a sense of DDD.

I have a case of two entities, each with their own identity (meaning they are Entity type of DDD objects, not ValueObjects): Country and Currency.

Currency can belong to many Countries (for example EUR). Country, on the other hand, can have only one 'currently active' Currency, which isn't necessarily the same Currency at all times (such example would be EU country, abandoning their own national currency for the EUR).

In a specific domain bounded context, I would need only:

I am trying to create a system for domain modelling in typescript, influenced strongly by Scott Wlaschin's Domain Modelling Made Functional which is based on F#.

I am having trouble finding the correct way to handle the passing around of generic properties, so that a generic object type can specify a property as being of some form of another generic type with out forcing resolution immediately. Very hard to explain in text so here is a code example of roughly the kind of thing I am trying to achieve:

I am trying to apply the ddd concepts to my go project

and then I have an entity with a nested struct like this:

First of all as for "simplified DDD/CQS pattern" I am referencing https://github.com/dotnet-architecture/eShopOnContainers example dotnet application (which is not "strict" DDD/CQRS). However I am not dotnet developer and my question is related to general design patterns / code organization.

My own case is as follows: I have "conference" domain with "conference" root aggregate and "conference_edition" aggregate. In RDBMS language conference has many editions. In this domain all "communication" with outside world is done through root aggregate "conference". So there are use cases like Conference.create(), Conference.addDraftEdition(), Conference.publishEdition() etc.

I have also "booking" domain which manages bookings for specific conference editions (people book tickets for a conference edition).

My question is related to the read model / aggregate of "conference" service (domain?). CMS of this application needs following read model for a conference (example in json for simplicity):

I am using EF Core and I have a scenario where the user can create a custom field and then creates options for that custom fields.

Sorry for my English, I am writing a real estate appraisal module and decided to try writing in the DDD paradigm. I looked at examples and different articles and formed the following picture for myself (simplified):

1. ApplicationCore.Domain - the core of business logic, contains all the necessary objects divided into 2 typesа
   Entitys - if an entity needs to be stored in a database and it is a ready-made complete business logic object. ValueObjects - all other properties that encapsulate the behavior, are compared by the value of the fields, and are part of Entity It is very important to create only valid objects, so I create everything through factories with a validator, and the constructors are private. There should be no references to other dependencies, as isolated as possible.

2. ApplicationCore.App - a layer above ApplicationCore.Domain, contains a link to it. works with objects from ApplicationCore.Domain and uses external services through Port/Adapter. Port - For example, an abstraction of a repository, its implementation through an Adapter on the Infrastructure layer.
   interaction logic for ApplicationCore is in AppServices - for classic implementation or in Command / Request - for CQRS

3. Infrastructure - contains a link to ApplicationCore.Domain and ApplicationCore.App. Implements the ports of the ApplicationCore.App layer

Entities are independent from each other and refer to each other by keys for interaction. I kept the basic logic of the assessment system in this paradigm. But here it was necessary to add a service that receives additional information for evaluation from different sources, while in wiretapping mode. Those. Works against the background of listening to TcpIp socket

Service settings are stored in the database and change frequently - i.e. you need to introduce a new Entity A chain is formed

From what I understand, records are actually classes that implement their own equality check in a way that your object is value-driven and not reference driven.

In short, for the record Foo that is implemented like so: var foo = new Foo { Value = "foo" } and var bar = new Foo { Value = "foo" }, the foo == bar expression will result in True, even though they have a different reference (ReferenceEquals(foo, bar) // False).

Now with records, even though that in the article posted in .Net Blog, it says:

If you don’t like the default field-by-field comparison behavior of the generated Equals override, you can write your own instead.

When I tried to place public override bool Equals, or public override int GetHashCode, or public static bool operator ==, and etc. I was getting Member with the same signature is already declared error, so I think that it is a restricted behaviour, which isn't the case with struct objects.

Failing example:

With so much talk about DDD, I've expected to find lot of code examples how these patterns are implemented. But wasn't so lucky.

What confuses me is this. Is an aggregate kind of entity, represented as aggregate root, or are those implemented as separate classes? Here are few examples, please answer if any of them is true.

1. They are separate classes