GET for reading resources in Rest API - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does the GET method do in REST APIs?

GET is used to request and read data from a server without changing it. It retrieves information like reading a book without writing in it.

beginner

Is GET request safe and idempotent? What does that mean?

Yes, GET is safe because it does not change data on the server. It is idempotent because making the same GET request multiple times gives the same result without side effects.

beginner

How do you specify which resource to read in a GET request?

You use the URL (Uniform Resource Locator) to point to the resource. For example, GET /books/123 reads the book with ID 123.

intermediate

Can GET requests have a body?

Usually, GET requests do not have a body. All information needed should be in the URL or query parameters.

beginner

What HTTP status code usually means a successful GET request?

Status code 200 means OK, which means the server successfully returned the requested resource.

What is the main purpose of a GET request in REST APIs?

A To delete data from the server

B To create new data on the server

C To read data from the server

D To update existing data on the server

GET requests are used to read or retrieve data without changing it.

Which HTTP status code indicates a successful GET request?

A 301

B 500

C 404

D 200

200 means OK, the resource was found and returned successfully.

Are GET requests supposed to change data on the server?

A No, they only read data

B Yes, always

C Sometimes, depends on the server

D Only if a body is sent

GET requests are safe and do not modify server data.

How do you specify which resource to get in a GET request?

A In the URL path or query parameters

B In the request body

C In the response headers

D By sending a POST first

The URL path or query parameters tell the server which resource to return.

What does it mean that GET requests are idempotent?

A They can only be sent once

B Multiple identical requests have the same effect as one

C They change data each time

D They require authentication

Idempotent means repeating the request does not change the result or server state.

Explain in your own words what a GET request does in REST APIs.

Think about how you read a book without writing in it.

Describe how you would use a GET request to retrieve a specific resource from a server.

Imagine asking a librarian for a specific book by its number.

Practice

1. What is the main purpose of a GET request in REST API?

easy

A. To read or fetch data from the server

B. To create new data on the server

C. To update existing data on the server

D. To delete data from the server

Solution

1. Step 1: Understand the HTTP methods

   GET is one of the HTTP methods used in REST APIs. It is specifically designed to retrieve data without changing it.

2. Step 2: Identify the purpose of GET

   GET requests fetch or read data from the server without modifying it, unlike POST, PUT, or DELETE.

3. Final Answer:

   To read or fetch data from the server -> Option A

4. Quick Check:

   GET = Read data [OK]

Hint: GET always fetches data without changing it [OK]

Common Mistakes:

• Confusing GET with POST which creates data
• Thinking GET deletes data
• Assuming GET updates data

2. Which of the following is the correct syntax for a GET request URL to fetch a user with ID 5?

easy

A. POST /users/5

B. POST /users?id=5

C. GET /users/5

D. DELETE /users/5

Solution

1. Step 1: Identify the HTTP method for reading

   GET is the correct method to read or fetch data, so the method must be GET.

2. Step 2: Check the URL path for resource

   /users/5 is the typical RESTful path to get a user with ID 5. Other options use wrong HTTP methods.

3. Final Answer:

   GET /users/5 -> Option C

4. Quick Check:

   GET + resource path = correct syntax [OK]

Hint: GET method + resource path fetches data [OK]

Common Mistakes:

• Using POST or DELETE instead of GET
• Using query parameters incorrectly
• Mixing HTTP methods and URLs

3. Given the following GET request URL: /products?category=books&limit=3, what does the server most likely return?

medium

A. All products without filtering

B. Products with category 'limit' and quantity 3

C. An error because of invalid query parameters

D. First 3 products in the books category

Solution

1. Step 1: Analyze the query parameters

   The URL has two query parameters: category=books and limit=3, which filter products by category and limit the number returned.

2. Step 2: Understand typical API behavior

   APIs commonly use 'category' to filter items and 'limit' to restrict the number of results returned.

3. Final Answer:

   First 3 products in the books category -> Option D

4. Quick Check:

   Query filters + limit = filtered limited results [OK]

Hint: Query params filter and limit results [OK]

Common Mistakes:

• Ignoring query parameters and returning all data
• Misreading 'limit' as a category
• Assuming query causes error

4. Identify the error in this GET request example: GET /users/ with body {"id": 10}

medium

A. The URL is missing the user ID

B. GET requests should not have a body

C. The HTTP method should be POST

D. The JSON body is missing a field

Solution

1. Step 1: Understand GET request rules

   GET requests do not send a body; they pass parameters via URL path or query string.

2. Step 2: Check the given request

   The request has a JSON body, which is invalid for GET and ignored by most servers.

3. Final Answer:

   GET requests should not have a body -> Option B

4. Quick Check:

   GET = no body allowed [OK]

Hint: GET requests never include a body [OK]

Common Mistakes:

• Adding body data to GET requests
• Confusing GET with POST or PUT
• Assuming URL must always include ID

5. You want to fetch a list of active users created after 2023-01-01 using a GET request. Which URL is the best choice?

hard

A. GET /users?status=active&created_after=2023-01-01

B. GET /users/active/2023-01-01

C. POST /users with body {"status":"active","created_after":"2023-01-01"}

D. GET /users {"status":"active","created_after":"2023-01-01"}

Solution

1. Step 1: Choose correct HTTP method and URL format

   GET is used to read data. Query parameters are the standard way to filter resources in GET requests.

2. Step 2: Analyze options for filtering

   GET /users?status=active&created_after=2023-01-01 uses query parameters to filter by status and creation date, which is the correct RESTful approach.

3. Final Answer:

   GET /users?status=active&created_after=2023-01-01 -> Option A

4. Quick Check:

   GET + query filters = correct usage [OK]

Hint: Use query parameters to filter GET requests [OK]

Common Mistakes:

• Using POST instead of GET for reading
• Putting filters in URL path incorrectly
• Sending body with GET request