Jesse Liberty

As noted in part 1 of this series, I will be building an application specifically to explore building APIs. To get started, I’ll want to build a back-end database. The application we’ll be simulating is a car dealership. Customers can list a car for sale, or look through cars they might buy.

We want to keep things very simple, so we will create a single table for now: Car

Car will have six columns

• id (int primary key)
• make (varchar 50)
• model (varchar 50)
• model_year (int)
• price (decimal)
• deleted (int)

By marking id as primary key you ensure two things: no two cars will have the same id, and each added row will have an incremented value. The deleted column allows us to have “soft” deletes — that is, we mark a row deleted but do not remove it from the table.

We can now insert a few rows:

insert into car
(make, model, model_year, price, deleted)
values ('Subaru', 'Imprezza', 2024 ,35500, 0),
('Subaru','Outback',2024,42000, 0),
('Prius','C',2022,25000, 0)

Note: I highly recommend the book SQL Pocket Guide (O’Reilly, Alice Zhao) for looking up how to do all the SQL operations I’ll show in these blog entries.

With this table, we can create endpoints for the CRUD (Create Read Update Delete) operations and more (e.g., obtaining a list of available vehicles).

In the next post, we’ll build our first endpoint to get a list of available cars.

While I’m still happily ensconced at CNH Industrial, I have changed my job. I’m no longer writing mobile applications (for the first time in about 7 years!) but rather am writing APIs using ASP.NET Core and C#. -The plan is to have a book on creating APIs (how-to, best practices, patterns, etc.) next year. In the interim, I’ll be writing a series of blog posts covering such topics as how to get started, software and tools you’ll need, REST, and much more.

As part of this series, I’ll create a dead-simple real-world example of a car selling and buying application, suggested by Daniel Brevitt (technical editor of .NET MAUI For C# Programmers). This application will consist of four major parts:

• The backend SQL Server database
• The front end for administrators (for inventory, etc.)
• The front end for customers (for buying or selling)
• The API that connects the front end to the back end

We’ll create a very simple SQL database using SQL Server and SSMS, and take advantage of Dapper: a simple ORM (Object Relational Model). We will not cover Entity Framework as our focus will be on the APIs, not the back end.

Similarly, the front end will be a very simple application — though at first I’ll simply use Postman rather than building out the front end. In fact, given how important and powerful Postman is, I may never get around to building a real front-end. Getting familiar with the Postman is more important for our purposes.

We will build three types of APIs

• Traditional APIs built using controllers in ASP.NET Core and .NET 7/8
• Minimal APIs
• Azure Functions

My focus in the first posts will be on the first two types, so that we can work locally without having to use Azure for now (there are tools for working with Azure functions locally, but we’ll hold off on that). In fact, we’ll create such a simple database that you can recreate it locally (and I’ll put all the code for this series up on GitHub).

For these posts, I anticipate developing on Windows using:

• Visual Studio 2022
• C# – probably nothing more advanced than C# 7 or 8, though bits of later versions may appear from time to time
• SQL Server (latest)
• SQL Server Management Studio (SSMS) that comes with SQL Server
• Postman (latest)
• Dapper (latest)
• AutoMapper

All of the software we’ll be using is free (the community editions are fine).

In the next post I’ll create the database and its preliminary tables.