Data

Tools

Indexes

Applications

Experiments

Awesome

An open API service indexing awesome lists of open source software.

https://github.com/brenordv/csharp-graphql-demo


https://github.com/brenordv/csharp-graphql-demo

Last synced: 3 months ago
JSON representation

Awesome Lists containing this project

README 

        
# GraphQL API and Client Project



## Overview



This project is a simple demonstration of a GraphQL API using HotChocolate and a client using Refit in .NET. 

It's a simple in-memory CRUD (Create, Read, Update, ~Delete~) application for product management.



**Note:** This is a minimal example, designed for educational purposes. It does not necessarily follow all best 

practices for production-ready software. Please ensure that you follow all best practices when creating production-ready

applications.



## What the Project Does



The project is a product management system. It enables you to:

- Add new products

- Fetch all products

- Fetch a specific product by ID

- Fetch products with ratings above a certain value

- Update existing products



Each product has the following properties:

- Id

- SoldBy

- Name

- Description

- Price

- ProductDesigner

- AddedToStoreAt

- LastShipmentReceivedAt

- SoldSinceAvailable

- IsAvailable

- Rating



## How to Use



Firstly, ensure that you have .NET 6.0 or later installed on your machine.



To run the GraphQL API:



1. Navigate to the GraphQL API directory in your terminal.

2. Run the command `dotnet run`.

3. You can then access the API at `http://localhost:5000/graphql` or run the client program.



To run the client:



1. Navigate to the client directory in your terminal.

2. Run the command `dotnet run`.

3. The client will automatically connect to the API, and you can use the client to send requests to the API.



The client includes methods for adding a product, fetching all products, fetching a specific product by its ID, and 

updating a product. You can use these methods as examples to build your own methods for interacting with the API.



## Best Practices



Remember, while this project serves as a basic demonstration, there are several best practices you should follow in a 

production environment. Here are some key points to consider:



- Use a real database: This project uses an in-memory database for simplicity. In a production environment, you should 

use a persistent database.

- Error Handling: The project has minimal error handling. Be sure to implement comprehensive error handling in 

your production applications.

- Testing: This project has no tests. In a production application, you should implement unit tests, integration tests, 

and possibly UI/end-to-end tests.

- Security: This project doesn't include any form of authentication or authorization. In real-world applications, 

you should secure your API, such as using JWTs or OAuth.

- Performance: Consider performance implications and optimizations for your GraphQL API. For example, use data loaders 

to batch and cache requests where appropriate.



## Conclusion



This is a simple demonstration of a GraphQL API and client in .NET. It provides a basic understanding of how to build 

and interact with a GraphQL API using the HotChocolate library and a client using the Refit library. Make sure to 

follow best practices when building production-ready applications.



# How does GraphQL work?

GraphQL operates as a query language for APIs, functioning as a middle layer between client and server, allowing 

clients to request exactly the data they need and nothing more. At its core, a GraphQL server operates by defining

types and fields on those types, and then providing functions for each field on each type. The client sends a string

in the form of a GraphQL query to the server, which contains the set of fields to be returned. The server processes 

the query, maps the fields to the corresponding functions, executes them, and then returns a response with the 

requested data to the client. This allows for efficient data loading and can significantly reduce the amount of data

that needs to be transferred over the network, making GraphQL a powerful tool for developing flexible and 

efficient APIs.



## What are GraphQL Queries and Mutations?



### GraphQL Queries



Queries in GraphQL are analogous to the GET request in REST APIs. They are used to fetch or retrieve data from the

server. They operate in a read-only fashion, meaning they are not supposed to change the data on the server.



A powerful feature of GraphQL queries is the ability to specify exactly what data you want. This makes GraphQL very

efficient, as clients can avoid fetching unnecessary data.



### GraphQL Mutations



Mutations in GraphQL are used to change data on the server, i.e., to create, update, or delete data. They are similar

to the POST, PUT, PATCH, and DELETE requests in REST APIs.



In contrast to REST, which treats these as distinct operations, GraphQL encapsulates all these operations under

mutations. The mutation name is then used to determine the exact operation to perform.



## Pros and Cons of Using GraphQL over REST API



### Pros



- **Efficient Data Loading**: With GraphQL, the client specifies exactly what data it needs, which can reduce the

  amount of data that needs to be transferred over the network.

- **Single Request**: Instead of making several requests to different endpoints, like in REST, GraphQL often allows you

  to retrieve all necessary data in a single request.

- **Strong Typing**: GraphQL APIs are strongly typed. This means each request can be checked at compile time, reducing

  the likelihood of errors.

- **Self-Documenting**: The schema of a GraphQL API is self-documenting. This means it can be easier to understand what

  data is available and how it can be queried or mutated.



### Cons



- **Complexity**: GraphQL introduces a higher level of complexity compared to REST. This can increase the learning

  curve for developers new to GraphQL.

- **Caching**: In REST, caching can be done with HTTP out-of-the-box, while in GraphQL it's not that straightforward.

- **File Uploads**: GraphQL does not natively support file uploads. This must be implemented with an additional

  specification or workaround.

- **Overkill for Simple APIs**: If the API is quite simple, GraphQL might be overkill. The benefits of GraphQL are

  more noticeable with large, complex APIs.



While GraphQL has many benefits over REST, it also has its drawbacks. The choice between using GraphQL and REST

depends on the specific requirements of the project. It's important to understand the needs of your project and the

trade-offs of each approach before deciding which one to use.