Filtering by field values in Rest API - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does filtering by field values mean in a REST API?

It means selecting only the data entries where specific fields match certain values. This helps get just the information you want from a large set.

beginner

How do you usually apply filtering in a REST API request?

You add query parameters to the URL that specify the field names and the values you want to filter by. For example, ?status=active filters results where the status field is 'active'.

beginner

Why is filtering by field values useful in real life?

Imagine you want to see only your unread emails or products in stock. Filtering helps you quickly find just those items without looking through everything.

intermediate

What is a common format for filtering multiple fields in a REST API?

You can add multiple query parameters, like ?status=active&category=books, to get items where status is 'active' and category is 'books'.

beginner

What happens if you don't use filtering in a REST API call?

You get all the data from the server, which can be slow and hard to handle if there is a lot of information. Filtering helps reduce this by sending only what you need.

How do you filter results by a field value in a REST API?

A By modifying the server code directly

B By changing the HTTP method to POST

C By using a different domain name

D By adding query parameters to the URL

Filtering is done by adding query parameters like '?field=value' to the URL.

What does the query parameter '?status=active' do?

A Deletes items with status 'active'

B Returns only items where status is 'active'

C Returns all items except those with status 'active'

D Changes the status of all items to 'active'

It filters the results to include only those with the status field equal to 'active'.

Which of these URLs filters by two fields: status and category?

A /items?filter=status=active,category=books

B /items/status/active/category/books

C /items?status=active&category=books

D /items?status=active|category=books

Using multiple query parameters separated by & is the standard way to filter by multiple fields.

Why is filtering important when requesting data from a REST API?

A To get only the data you need and improve speed

B To increase the amount of data returned

C To change the data on the server

D To avoid using query parameters

Filtering reduces data size and speeds up responses by sending only relevant data.

If you want to see only products priced below $20, what would you do?

A Use a query parameter like '?price_lt=20'

B Send a POST request with price=20

C Filter after receiving all products on the client

D Change the API endpoint to /cheap-products

Many APIs use query parameters like 'price_lt' to filter values less than 20.

Explain how filtering by field values works in a REST API and why it is useful.

Think about how you ask for only certain items from a big list.

Describe how you would filter a list of items by multiple fields in a REST API request.

Remember how URLs can have more than one question mark parameter.