Chapter 23: CRUD: Create in C#

Insert rows with auto-increment IDs. In this chapter, you will learn crud: create in depth with C# code examples, explanations, and best practices.

Overview

This chapter covers crud: create for Kungfu.js developers using C#. We will start with the basics, move through practical examples, and end with advanced techniques and common pitfalls.

Why This Matters

Understanding crud: create is essential because it is a core part of building web applications. Every real-world app needs to handle insert rows with auto-increment ids. Skipping this chapter would leave a gap in your knowledge that would cause problems later.

Code Example

Here is how to work with databases in C#:

let user = User {
    id: 0,  // auto-assigned by database
    email: "alice@example.com".into(),
    password: "secure_password".into(),
    computed_field: String::new(),
};
let created = user.insert(&db).await?;
println!("Created user with id={}", created.id);

How the ORM Works

The Kungfu.js ORM uses parameterized queries. This means user input never gets interpolated into SQL strings. Instead, placeholders like $1, $2 are used, and the actual values are passed separately. This makes SQL injection impossible.

For example, if you search for a user by email, the ORM generates: SELECT * FROM users WHERE email = $1 and passes the email value as a parameter. Even if the email contains SQL code like ' OR 1=1 --, it is treated as a plain string, not as SQL.

Common Mistakes

• Not reading the documentation: Always check the API reference when something does not work as expected.
• Skipping security: Never disable the default middleware unless you have a very good reason. Security is not optional.
• Not testing: Write tests for your handlers. Kungfu.js makes this easy with the built-in test utilities.

Summary

In this chapter, you learned about crud: create in C#. You saw code examples, understood how things work under the hood, and learned about common mistakes to avoid.

What is Next?

In chapter 24, we will cover CRUD: Read: Query rows with WHERE, ORDER, LIMIT.