Why flexible querying empowers clients in Rest API - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to add a query parameter for filtering users by age.

Rest API

GET /users?age=[1]

Drag options to blanks, or click blank then click option'

Asort

B30

Climit

Dfilter

Attempts:

3 left

💡 Hint

Common Mistakes

Using parameter names instead of values

Using unrelated query parameters

The query parameter 'age=30' filters users who are 30 years old.

2fill in blank

medium

Complete the code to limit the number of results returned by the API.

Rest API

GET /products?[1]=10

Drag options to blanks, or click blank then click option'

Asort

Bfilter

Climit

Doffset

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'filter' or 'sort' instead of 'limit'

The 'limit' parameter restricts the number of results returned to 10.

3fill in blank

hard

Fix the error in the query parameter to sort users by name ascending.

Rest API

GET /users?sort=[1]

Drag options to blanks, or click blank then click option'

A-name

Basc

Cdesc

Dname

Attempts:

3 left

💡 Hint

Common Mistakes

Using '-name' for ascending order

Using 'asc' which is not accepted here

Using 'name' sorts users by name in ascending order. A leading '-' would sort descending.

4fill in blank

hard

Fill both blanks to filter products by category and sort by price descending.

Rest API

GET /products?[1]=electronics&[2]=-price

Drag options to blanks, or click blank then click option'

Afilter

Bcategory

Csort

Dlimit

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'filter' as a parameter name instead of 'category'

Using 'limit' instead of 'sort'

'category=electronics' filters products in the electronics category, and 'sort=-price' sorts them by price descending.

5fill in blank

hard

Fill all three blanks to create a query that filters users by active status, limits results to 5, and sorts by signup date ascending.

Rest API

GET /users?[1]=true&[2]=5&[3]=signup_date

Drag options to blanks, or click blank then click option'

Aactive

Blimit

Csort

Dstatus

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'status' instead of 'active'

Using 'sort' as a value instead of parameter name

'active=true' filters active users, 'limit=5' restricts results to 5 users, and 'sort=signup_date' sorts by signup date ascending.

Practice

1. Why does flexible querying empower clients in a REST API?

easy

A. It makes the server slower by processing more data.

B. It forces clients to download all data regardless of need.

C. It allows clients to request only the data they need, reducing data transfer.

D. It disables filtering and sorting options for clients.

Solution

1. Step 1: Understand flexible querying purpose

   Flexible querying lets clients specify exactly what data they want.

2. Step 2: Identify benefit to clients

   This reduces unnecessary data transfer and speeds up responses.

3. Final Answer:

   It allows clients to request only the data they need, reducing data transfer. -> Option C

4. Quick Check:

   Flexible querying = request needed data only [OK]

Hint: Flexible querying means ask only for needed data [OK]

Common Mistakes:

• Thinking flexible querying sends all data always
• Believing it slows down the server
• Confusing filtering with disabling options

2. Which of the following is the correct way to request only the 'name' and 'email' fields using query parameters?

easy

A. /users?fields=name,email

B. /users?filter=name,email

C. /users?sort=name,email

D. /users?select=name,email

Solution

1. Step 1: Identify query parameter for selecting fields

   The 'fields' parameter is used to specify which fields to return.

2. Step 2: Match correct syntax

   Using 'fields=name,email' correctly requests only those fields.

3. Final Answer:

   /users?fields=name,email -> Option A

4. Quick Check:

   fields param selects fields [OK]

Hint: Use 'fields' param to pick specific data fields [OK]

Common Mistakes:

• Using 'filter' to select fields instead of filter data
• Using 'sort' to select fields
• Using 'select' which is not standard here

3. Given the API endpoint /products?filter=price>20&sort=price, what is the expected behavior?

medium

A. Return products with price greater than 20, sorted by price ascending.

B. Return all products ignoring the filter and sort parameters.

C. Return products with price less than 20, sorted by price descending.

D. Cause a syntax error due to invalid query format.

Solution

1. Step 1: Analyze the filter parameter

   The filter 'price>20' means select products priced above 20.

2. Step 2: Analyze the sort parameter

   The sort 'price' means sort results by price in ascending order by default.

3. Final Answer:

   Return products with price greater than 20, sorted by price ascending. -> Option A

4. Quick Check:

   filter price>20 + sort price ascending = Return products with price greater than 20, sorted by price ascending. [OK]

Hint: Filter narrows data; sort orders it [OK]

Common Mistakes:

• Confusing greater than with less than
• Assuming sort defaults to descending
• Thinking query causes syntax error

4. A client sends a request /orders?filter=status=shipped&fields=id,total but receives all fields in the response. What is the likely issue?

medium

A. The filter syntax is incorrect and causes the server to ignore parameters.

B. The 'status=shipped' filter is invalid and returns all data.

C. The client must use 'select' instead of 'fields' to limit fields.

D. The server does not support the 'fields' parameter.

Solution

1. Step 1: Check server support for 'fields'

   If the server ignores 'fields', it returns all fields regardless of query.

2. Step 2: Validate filter syntax

   The filter syntax 'status=shipped' is correct and should work if supported.

3. Final Answer:

   The server does not support the 'fields' parameter. -> Option D

4. Quick Check:

   Unsupported 'fields' param = all fields returned [OK]

Hint: If fields param ignored, server likely lacks support [OK]

Common Mistakes:

• Assuming filter syntax error causes ignoring fields
• Thinking 'select' is required instead of 'fields'
• Believing invalid filter returns all data

5. You want to build a REST API endpoint that lets clients filter products by category, sort by price descending, and select only 'id', 'name', and 'price' fields. Which query string correctly enables this flexible querying?

hard

A. /products?filter=category=electronics&sort=price_desc&fields=id|name|price

B. /products?filter=category=electronics&sort=-price&fields=id,name,price

C. /products?category=electronics&order=desc_price&select=id,name,price

D. /products?filter=category:electronics&sort=price-desc&fields=id;name;price

Solution

1. Step 1: Identify correct filter syntax

   Filter uses 'filter=category=electronics' to select category.

2. Step 2: Identify correct sort syntax

   Sort '-price' means descending by price.

3. Step 3: Identify correct fields syntax

   Fields are comma-separated: 'fields=id,name,price'.

4. Final Answer:

   /products?filter=category=electronics&sort=-price&fields=id,name,price -> Option B

5. Quick Check:

   filter + sort desc + fields comma = /products?filter=category=electronics&sort=-price&fields=id,name,price [OK]

Hint: Use filter=, sort=- for descending, fields=comma list [OK]

Common Mistakes:

• Using wrong separators like ; or |
• Incorrect sort syntax like 'price-desc' or 'price_desc'
• Using 'select' instead of 'fields'