Bulk import and export in Rest API - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output of this bulk import API response?

Consider a REST API endpoint that accepts a JSON array of user objects for bulk import. The server responds with a summary JSON object showing how many users were successfully imported and how many failed.

Given the following server response after sending 5 user objects, what is the output?

Rest API

{
  "imported": 4,
  "failed": 1,
  "errors": [
    {"index": 3, "message": "Email already exists"}
  ]
}

A {"imported":4,"failed":1,"errors":[{"index":3,"message":"Email already exists"}]}

B {"imported":5,"failed":0,"errors":[]}

C {"imported":3,"failed":2,"errors":[{"index":1,"message":"Invalid data"},{"index":4,"message":"Missing field"}]}

D {"imported":0,"failed":5,"errors":[{"index":0,"message":"Server error"}]}

💡 Hint

Look carefully at the numbers and error details in the JSON response.

The server response shows 4 users imported successfully and 1 failed with an error at index 3. This matches option A exactly.

🧠 Conceptual

intermediate

Which HTTP method is best suited for bulk export of data?

You want to design a REST API endpoint that allows clients to export large amounts of data in bulk. Which HTTP method should you use?

A GET

B PUT

C POST

D DELETE

💡 Hint

Think about which method is used to retrieve data without changing server state.

GET is the standard HTTP method to retrieve data. For bulk export, clients request data without modifying it, so GET is appropriate.

🔧 Debug

advanced

Why does this bulk import request fail with a 400 error?

Here is a JSON payload sent to a bulk import API:

[{"id":1,"name":"Alice"},{"id":2,"name":"Bob"}, {"id":3,"name":null}]

The server responds with HTTP 400 Bad Request. What is the most likely cause?

A The 'id' fields are not unique.

B The third object has a null value for the 'name' field which is required.

C The JSON array is missing a closing bracket.

D The server does not accept arrays, only single objects.

💡 Hint

Check the data values carefully for required fields.

The 'name' field is likely required and cannot be null. This causes the server to reject the request with 400.

📝 Syntax

advanced

Which JSON payload is correctly formatted for bulk export request filters?

You want to request a bulk export with filters on user status and creation date. Which JSON payload is syntactically correct?

A {"filters": {"status" => "active", "created_after" => "2023-01-01"}}

B {"filters": ["status": "active", "created_after": "2023-01-01"]}

C {"filters": {status: "active", created_after: "2023-01-01"}}

D {"filters": {"status": "active", "created_after": "2023-01-01"}}

💡 Hint

Remember JSON requires double quotes around keys and string values, and uses colons, not arrows.

Option D uses correct JSON syntax with double quotes and colons. Options A, B, and C have syntax errors.

🚀 Application

expert

How many user records will be created after this bulk import API call?

An API accepts a bulk import POST request with this JSON payload:

[{"id":1,"email":"[e-mail]"},{"id":2,"email":"[e-mail]"},{"id":3,"email":"[e-mail]"},{"id":4,"email":"[e-mail]"}]

The API rejects duplicates by email and skips them silently. How many user records will be created?

A 1

B 4

C 3

D 2

💡 Hint

Count unique emails only, duplicates are skipped.

Emails are: [e-mail] (twice), [e-mail], [e-mail]. The duplicate '[e-mail]' is skipped once, so 3 unique users are created.