Introduction

This is a sample API, using Clean Architecture, CQRS and Microsoft .NET 7.

We are using some Functional Programing paradigms, concepts such as:

• Maybe<T> - to avoid Nulls with the Maybe Type
• Result - to handle failures and Input Errors in a Functional Way

Context

The application is an API for a student management system. Here's the domain model of this system. This is the main class in our model, Student. It consists of a name, email, collection of enrollments, and a collection of disenrollment comments. A student can have up to two enrollments in courses. Each enrollment has a grade: either A, B, C, D, or F. Whenever the user deletes an enrollment, he or she must specify the reason why the student wants to discontinue taking this course. It means that when you create an enrollment, you must specify the student's grade, and when you delete one, you have to type in the comment from the student. The API exposes the standard CRUD operations: the standard create, read, update, and delete.

Domain

Persistence layer

We have 3 repositories, and we are using the unit of work pattern:

• StudentRepository
• CourseRepository
• EnrollmenttRepository

Api layer

Courses endpoints

• GET /Courses - returns all courses
• POST /Courses - creates a new course
• GET /Courses/{id} - returns a course by id
• GET /Courses/GetByName/{name} - returns a course by name
• DELETE /Courses/{id} - deletes a course by id

Enrollments endpoints

• GET /Enrollments - returns all enrollments

Students endpoints

• GET /students - returns all students
• POST /students - creates a new student
• DELETE /students/{id} - deletes a student by id
• PUT /students/{id} - updates a student by id
• POST /students/{id}/enrollments - adds a student to a course
• PUT /students/{id}/enrollments/{enrollmentNumber} - updates a student with a course
• POST /students/{id}/enrollments/{enrollmentNumber}/deletion - deletes a student from a course

Request validations (using Fluent Validation)

Student

• Id should not be null
• Name should not be empty
• Email should not be empty

Enrollment

• Id should not be null
• Student should not be empty
• Course should not be empty
• Grade should not be empty

Course

• Id should not be null
• Name should not be empty
• Credits should not be null

Technologies

This demo application uses the following technologies:

• .NET 7
• C# 11
• ASP.NET Core MVC 7.0
• EF Core 7.0
• Rider 2022
• SQL Server 2022
• MediatR 11.1
• Fluent Validation 11.2
• Bogus 34.0