HTTP Methods: CRUD Operations

In e-commerce, you need to Create orders, Read products, Update cart quantities, and Delete items. Each action uses a different HTTP method.

The CRUD-HTTP Mapping

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GET - Read Data

We covered GET in the previous lesson. Quick recap:

GET /api/products          → List all products
GET /api/products/123      → Get specific product
GET /api/products?category=electronics → Filter

• ✅ Safe - doesn't modify data
• ✅ Cacheable - browsers can cache responses
• ✅ No request body

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POST - Create Data

POST creates new resources. Let's add an item to a cart:

Adding to Cart

• New request → Select POST
• URL: https://fakestoreapi.com/carts
• Go to Body tab
• Select raw and JSON
• Enter:

{
  "userId": 1,
  "date": "2024-01-15",
  "products": [
    { "productId": 5, "quantity": 2 },
    { "productId": 1, "quantity": 3 }
  ]
}

• Click Send

{
  "id": 21,
  "userId": 1,
  "date": "2024-01-15",
  "products": [
    { "productId": 5, "quantity": 2 },
    { "productId": 1, "quantity": 3 }
  ]
}

Notice:

• Status is 201 Created (not 200)
• Response includes the new id assigned by the server

Creating a User Account

POST https://fakestoreapi.com/users

Body:

{
  "email": "john@example.com",
  "username": "johndoe",
  "password": "secure123",
  "name": {
    "firstname": "John",
    "lastname": "Doe"
  },
  "address": {
    "city": "San Francisco",
    "street": "123 Main St",
    "zipcode": "94102"
  },
  "phone": "1-555-123-4567"
}

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PUT - Replace Entire Resource

PUT replaces the entire resource. If you omit a field, it may be deleted.

Update Entire Cart

PUT https://fakestoreapi.com/carts/7

Body:

{
  "userId": 1,
  "date": "2024-01-16",
  "products": [
    { "productId": 3, "quantity": 1 }
  ]
}

This replaces the entire cart - previous items are gone!

{
  "id": 7,
  "userId": 1,
  "date": "2024-01-16",
  "products": [
    { "productId": 3, "quantity": 1 }
  ]
}

Update User Profile

PUT https://fakestoreapi.com/users/1

Body:

{
  "email": "newemail@example.com",
  "username": "johndoe",
  "password": "newpassword",
  "name": {
    "firstname": "John",
    "lastname": "Smith"
  },
  "address": {
    "city": "Los Angeles",
    "street": "456 Oak Ave",
    "zipcode": "90001"
  },
  "phone": "1-555-987-6543"
}

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PATCH - Partial Update

PATCH updates only the fields you send - other fields remain unchanged.

Update Just the Quantity

PATCH https://fakestoreapi.com/carts/7

Body (only what's changing):

{
  "products": [
    { "productId": 3, "quantity": 5 }
  ]
}

Other cart fields (userId, date) stay the same.

PUT vs PATCH

Updating shipping address:

• PUT: Send entire order object (items, payment, shipping)
• PATCH: Send just { "shippingAddress": {...} }

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DELETE - Remove Data

DELETE removes a resource.

Remove from Cart

DELETE https://fakestoreapi.com/carts/7

No body needed!

{
  "id": 7,
  "userId": 1,
  "date": "...",
  "products": [...]
}

Many APIs return the deleted resource for confirmation.

Delete User Account

DELETE https://fakestoreapi.com/users/1

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Complete E-commerce Flow

Let's walk through a typical shopping flow:

1. Browse Products (GET)

GET /api/products?category=electronics

2. Add to Cart (POST)

POST /api/carts
{
  "userId": 1,
  "products": [{ "productId": 5, "quantity": 1 }]
}

3. Update Quantity (PATCH)

PATCH /api/carts/21
{
  "products": [{ "productId": 5, "quantity": 3 }]
}

4. Remove Item (DELETE)

DELETE /api/carts/21/items/5

5. Place Order (POST)

POST /api/orders
{
  "cartId": 21,
  "paymentMethod": "card",
  "shippingAddress": {...}
}

6. Check Order Status (GET)

GET /api/orders/99

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Practice Exercises

Exercise 1: Create a Product (POST)

POST https://fakestoreapi.com/products

Body:

{
  "title": "Wireless Bluetooth Headphones",
  "price": 79.99,
  "description": "High-quality wireless headphones with noise cancellation",
  "image": "https://example.com/headphones.jpg",
  "category": "electronics"
}

Save as: Create Product in Products folder

Exercise 2: Update Product Price (PATCH)

PATCH https://fakestoreapi.com/products/7

Body:

{
  "price": 59.99
}

Save as: Update Product Price

Exercise 3: Delete a Product (DELETE)

DELETE https://fakestoreapi.com/products/7

Save as: Delete Product

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Common Testing Scenarios

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Key Takeaways

Next up: Request Parameters & Headers - passing data and authentication!