References

Official Documentation

Functorium

• GitHub: https://github.com/hhko/Functorium
• Repository types: Src/Functorium/Domains/Repositories/
• Query adapters: Src/Functorium/Applications/Queries/
• Usecase interfaces: Src/Functorium/Applications/Usecases/

.NET

• Entity Framework Core: https://learn.microsoft.com/en-us/ef/core/
• Dapper: https://github.com/DapperLib/Dapper

LanguageExt

• GitHub: https://github.com/louthy/language-ext
• FinT documentation: https://github.com/louthy/language-ext/wiki

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Books

Domain-Driven Design

• Title: Domain-Driven Design: Tackling Complexity in the Heart of Software
• Author: Eric Evans
• Publisher: Addison-Wesley, 2003
• Key content: Foundational definitions of Entity, Aggregate Root, Repository, and Specification patterns

Implementing Domain-Driven Design

• Title: Implementing Domain-Driven Design
• Author: Vaughn Vernon
• Publisher: Addison-Wesley, 2013
• Key content: Practical DDD implementation, CQRS and Event Sourcing

Patterns of Enterprise Application Architecture

• Title: Patterns of Enterprise Application Architecture
• Author: Martin Fowler
• Publisher: Addison-Wesley, 2002
• Key content: Repository pattern, Unit of Work pattern, Query Object pattern

Functional Programming in C#

• Title: Functional Programming in C#: How to write better C# code
• Author: Enrico Buonanno
• Publisher: Manning, 2022 (2nd Edition)
• Key content: Functional programming, monads, error handling

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Online Resources

CQRS

Greg Young’s CQRS Documents

• https://cqrs.files.wordpress.com/2010/11/cqrs_documents.pdf
• The original document on the CQRS pattern. Theoretical foundations of Command and Query separation.

Martin Fowler’s CQRS

• https://martinfowler.com/bliki/CQRS.html
• A concise explanation of the CQRS pattern and application guide.

Microsoft CQRS Pattern

• https://learn.microsoft.com/en-us/azure/architecture/patterns/cqrs
• Microsoft’s CQRS pattern explanation and application on Azure.

DDD & Repository Pattern

Martin Fowler’s Repository Pattern

• https://martinfowler.com/eaaCatalog/repository.html
• Definition and explanation of the Repository pattern.

Martin Fowler’s Unit of Work

• https://martinfowler.com/eaaCatalog/unitOfWork.html
• Definition of the Unit of Work pattern.

Specification Pattern

Eric Evans & Martin Fowler’s Specification Pattern

• https://www.martinfowler.com/apsupp/spec.pdf
• The original paper on the Specification pattern. Used as search criteria in IQueryPort.

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Related Libraries

CQRS & Mediator

Library	Description	NuGet
Functorium	The CQRS framework for this tutorial	-
Mediator	Source Generator-based Mediator pattern	Yes

ORM & Data Access

Library	Description	NuGet
Microsoft.EntityFrameworkCore	EF Core ORM (Command side)	Yes
Dapper	Lightweight ORM (Query side)	Yes

Functional Programming

Library	Description	NuGet
LanguageExt.Core	Functional programming types (Fin, FinT, IO)	Yes

Testing

Library	Description	NuGet
xUnit	Test framework	Yes
Shouldly	Assertion library	Yes
NSubstitute	Mock library	Yes

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Functorium Project Reference

Source Code Locations

Src/Functorium/
├── Domains/
│   ├── Entities/                  # Entity<TId>, AggregateRoot<TId>, IEntityId
│   ├── Repositories/              # IRepository<TAggregate, TId>
│   └── Specifications/            # Specification<T>
├── Applications/
│   ├── Queries/                   # IQueryPort<TEntity, TDto>
│   ├── Usecases/                  # ICommandRequest, IQueryRequest, FinResponse
│   └── Persistence/               # IUnitOfWork, IUnitOfWorkTransaction
Src/Functorium.Adapters/
├── Repositories/                  # InMemoryRepositoryBase, EfCoreRepositoryBase
├── Events/                        # DomainEventCollector
└── Observabilities/Pipelines/     # UsecaseTransactionPipeline

Tutorial Projects

Docs.Site/src/content/docs/tutorials/cqrs-repository/
├── Part1-Domain-Entity-Foundations/   # Domain entities (4)
├── Part2-Command-Repository/          # Repository pattern (4)
├── Part3-Query-Patterns/              # Query patterns (5)
├── Part4-CQRS-Usecase-Integration/    # Usecase integration (5)
└── Part5-Domain-Examples/             # Practical examples (4)

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Related Tutorials

This tutorial is more effective when studied alongside the following tutorials:

• Implementing Domain Rules with the Specification Pattern: From Specification pattern basics to Repository integration. In this tutorial, IQueryPort and IRepository use Specification as a parameter.

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Recommended Learning Order

Beginner (Pattern introduction)

1. Repository chapter from Eric Evans’ DDD book
2. Part 1 of this tutorial
3. Read Functorium Repository/Entity source code

Intermediate (Practical application)

1. Martin Fowler’s CQRS document
2. Parts 2~3 of this tutorial
3. EF Core / Dapper official documentation

Advanced (Architecture design)

1. Greg Young’s CQRS Documents
2. Parts 4~5 of this tutorial
3. Advanced study of LanguageExt functional types

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This tutorial was written based on real-world CQRS framework development experience with the Functorium project.