Sparse fieldsets (select fields) in Rest API - Cheat Sheet & Quick Revision

Recall & Review

beginner

What are sparse fieldsets in REST APIs?

Sparse fieldsets let clients ask for only specific fields of a resource instead of the whole data. This helps reduce the amount of data sent over the network.

beginner

How do you request sparse fieldsets in a REST API?

You add a query parameter like fields with a list of fields you want. For example, ?fields=name,email asks for only the name and email fields.

beginner

Why use sparse fieldsets in API responses?

Using sparse fieldsets reduces data size, speeds up responses, and lowers bandwidth use. It also helps clients get only the data they need, making apps faster and simpler.

beginner

Example: How to request only 'title' and 'author' fields for a book resource?

Use a URL like /books/123?fields=title,author. The server will return only the title and author fields for book 123.

intermediate

What happens if you request a field that does not exist in sparse fieldsets?

The server usually ignores unknown fields or returns an error. It depends on the API design, but ignoring unknown fields is common to keep responses stable.

What is the main benefit of using sparse fieldsets in REST APIs?

A Reducing the amount of data sent in responses

B Increasing the number of API endpoints

C Adding more fields to the response

D Changing the HTTP method

Sparse fieldsets reduce data size by sending only requested fields, improving performance.

How do you specify which fields to return in a sparse fieldset request?

A Using a custom HTTP header

B Changing the HTTP method to POST

C Using a query parameter like ?fields=field1,field2

D Adding fields in the request body

You use a query parameter, commonly named 'fields', listing the desired fields separated by commas.

If you request a field that does not exist, what usually happens?

A The server ignores the unknown field or returns an error

B The server returns all fields instead

C The server crashes

D The server deletes the resource

Most APIs ignore unknown fields or return an error to keep responses consistent.

Which HTTP method is typically used with sparse fieldsets?

A POST

B DELETE

C PUT

D GET

Sparse fieldsets are used with GET requests to fetch only selected fields.

What is a common format for specifying multiple fields in sparse fieldsets?

A XML in the request body

B Comma-separated list in a query parameter

C JSON array in the URL

D Multiple HTTP headers

A comma-separated list in a query parameter like ?fields=field1,field2 is standard.

Explain what sparse fieldsets are and why they are useful in REST APIs.

Think about how you can ask for only what you need from a menu instead of the whole menu.

Describe how to request specific fields from a REST API using sparse fieldsets.

Imagine telling a waiter exactly which dishes you want from a big menu.