crud create read update delete

Guri Bee

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20-10-2024

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CRUD: The Foundation of Web Development (And How It's Used Every Day)

Ever wondered how websites store and manage information? You can thank CRUD operations, the backbone of most dynamic web applications. CRUD stands for Create, Read, Update, and Delete, representing the fundamental actions we take on data.

Imagine a simple online store:

• Create: Adding a new product to the store's inventory
• Read: Viewing product details, browsing the catalog, or checking your order history
• Update: Modifying product descriptions, changing prices, or updating your shipping address
• Delete: Removing a product that's no longer available or canceling an order

But how does CRUD work under the hood? Let's dive deeper:

1. Create

Question: How can I create a new product in a database using SQL?

Answer from GitHub user:

INSERT INTO products (name, price, description) 
VALUES ('New Product', 19.99, 'This is a great product!'); 

Explanation:

• INSERT INTO: This command tells the database to add new data.
• products: The table where we want to insert the data.
• name, price, description: The columns we're filling with new values.
• VALUES: The actual data to be inserted.

Example:

Say we have a table named users with columns name, email, and password. To add a new user:

INSERT INTO users (name, email, password) 
VALUES ('John Doe', '[email protected]', 'securepassword');

2. Read

Question: How can I retrieve all products with prices under $10?

Answer from GitHub user:

SELECT * FROM products WHERE price < 10;

Explanation:

• SELECT: This command tells the database to retrieve data.
• *: We want to select all columns.
• FROM products: From the products table.
• WHERE price < 10: This is a condition to filter the results, only showing products with prices below $10.

Example:

To get all users with the email domain example.com:

SELECT * FROM users WHERE email LIKE '%@example.com';

3. Update

Question: How can I increase the price of a specific product by 5%?

Answer from GitHub user:

UPDATE products SET price = price * 1.05 WHERE name = 'Product Name';

Explanation:

• UPDATE products: The table to be updated.
• SET price = price * 1.05: Update the price column by multiplying its current value by 1.05.
• WHERE name = 'Product Name': Only update the product with the specific name.

Example:

To change a user's password:

UPDATE users SET password = 'newpassword' WHERE email = '[email protected]';

4. Delete

Question: How can I remove a product from the inventory?

Answer from GitHub user:

DELETE FROM products WHERE name = 'Product Name';

Explanation:

• DELETE FROM products: Delete data from the products table.
• WHERE name = 'Product Name': Delete only the product with the specified name.

Example:

To remove a user from the database:

DELETE FROM users WHERE email = '[email protected]'; 

Beyond the Basics:

CRUD operations are a fundamental building block for web development. Mastering them is essential for creating dynamic and interactive web applications. While we've focused on SQL examples, CRUD principles apply to many other technologies, including databases, APIs, and object-oriented programming.

Understanding CRUD empowers you to:

• Build complex web applications with ease.
• Efficiently manage data in your projects.
• Communicate effectively with other developers.

Keep exploring and learning, and you'll be well on your way to becoming a proficient web developer!