Batch create endpoint design in Rest API - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define the HTTP method for a batch create endpoint.

Rest API

app.[1]('/items/batch', create_items_batch)

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

ADELETE

BPUT

CPOST

DGET

Attempts:

3 left

💡 Hint

Common Mistakes

Using GET instead of POST for creating resources.

Using DELETE or PUT which are for other operations.

The batch create endpoint should use the POST method because it is used to create new resources.

2fill in blank

medium

Complete the code to accept a list of items in the request body for batch creation.

Rest API

def create_items_batch():
    items = request.[1]

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

Aargs

Bjson

Cform

Dheaders

Attempts:

3 left

💡 Hint

Common Mistakes

Using request.args which reads query parameters instead of body.

Using request.form which is for form data, not JSON.

request.json is used to get JSON data from the request body, which is typical for batch create endpoints.

3fill in blank

hard

Fix the error in the batch create function to correctly iterate over the items list.

Rest API

def create_items_batch():
    items = request.json
    for [1] in items:
        save_item(item)
    return {'status': 'success'}

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

Aitems

Bdata

Ci

Ditem

Attempts:

3 left

💡 Hint

Common Mistakes

Using the list variable name as the loop variable.

Using an undefined variable inside the loop.

The loop variable should be a single item, here named 'item', to iterate over the list 'items'.

4fill in blank

hard

Fill both blanks to validate each item has a 'name' key and return error if missing.

Rest API

def create_items_batch():
    items = request.json
    for item in items:
        if [1] not in item:
            return [2]
    return {'status': 'success'}

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

A'name'

B{'error': 'Missing name'}

C'id'

D{'error': 'Invalid data'}

Attempts:

3 left

💡 Hint

Common Mistakes

Checking wrong keys like 'id' instead of 'name'.

Returning a generic error message instead of specific.

We check if 'name' key is missing in each item and return a specific error message if so.

5fill in blank

hard

Fill all three blanks to create a batch endpoint that saves items and returns count of created items.

Rest API

def create_items_batch():
    items = request.[1]
    count = 0
    for [2] in items:
        save_item([3])
        count += 1
    return {'created': count}

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

Ajson

Bitem

Dargs

Attempts:

3 left

💡 Hint

Common Mistakes

Using request.args instead of request.json.

Using different variable names inconsistently.

The function reads JSON data, iterates over each item, saves it, and counts how many were created.

Practice

1. What HTTP method is typically used for a batch create endpoint in a REST API?

easy

A. DELETE

B. POST

C. GET

D. PUT

Solution

1. Step 1: Understand HTTP methods for data creation

   POST is used to create new resources on the server.

2. Step 2: Apply to batch create context

   Batch create sends multiple new items in one POST request.

3. Final Answer:

   POST -> Option B

4. Quick Check:

   Batch create uses POST [OK]

Hint: Batch create always uses POST method [OK]

Common Mistakes:

• Using GET which is for reading data
• Using DELETE which removes data
• Using PUT which replaces resources

2. Which of the following is the correct JSON format for sending multiple items in a batch create request body?

easy

A. {"name": "item1", "name": "item2"}

B. [{"name": "item1"}, {"name": "item2"}]

C. {"items": [{"name": "item1"}, {"name": "item2"}]}

D. {"item1": "name", "item2": "name"}

Solution

1. Step 1: Identify JSON array structure for batch data

   Batch create expects an object with a key containing an array of items.

2. Step 2: Match correct JSON format

   {"items": [{"name": "item1"}, {"name": "item2"}]} is a JSON object with an array of objects, which is correct for batch create.

3. Final Answer:

   {"items": [{"name": "item1"}, {"name": "item2"}]} -> Option C

4. Quick Check:

   Batch create body = JSON object with items array [OK]

Hint: Batch create body is a JSON object with an array of items [OK]

Common Mistakes:

• Using duplicate keys in one object
• Sending a single object instead of an array
• Using incorrect JSON syntax

3. Given this batch create endpoint code snippet, what will be the response if one item is invalid?

POST /items/batch
Request body: [{"name": "item1"}, {"name": ""}]

Response: 400 Bad Request
{
  "error": "Validation failed",
  "details": [{"index": 1, "message": "Name cannot be empty"}]
}

medium

A. Server crashes due to invalid input

B. All items are created, ignoring the invalid one

C. Only the valid items are created, error ignored

D. No items are created, and error details are returned

Solution

1. Step 1: Understand validation behavior in batch create

   If any item is invalid, the server should reject the whole batch to keep data consistent.

2. Step 2: Analyze the response code and message

   Response 400 with error details means no items were created and client is informed.

3. Final Answer:

   No items are created, and error details are returned -> Option D

4. Quick Check:

   Validation failure returns 400 with errors [OK]

Hint: Validation errors cause full batch rejection [OK]

Common Mistakes:

• Assuming partial success without error
• Ignoring error details in response
• Expecting server to crash on bad input

4. You wrote a batch create endpoint but clients report that sending an empty array causes a 500 Internal Server Error. What is the likely fix?

medium

A. Add validation to return 400 Bad Request if array is empty

B. Change HTTP method from POST to GET

C. Remove JSON parsing from the endpoint

D. Allow empty arrays and return 204 No Content

Solution

1. Step 1: Identify cause of 500 error on empty input

   Server likely crashes because it does not handle empty arrays properly.

2. Step 2: Implement input validation for empty arrays

   Return 400 Bad Request to inform client that empty batch is invalid.

3. Final Answer:

   Add validation to return 400 Bad Request if array is empty -> Option A

4. Quick Check:

   Validate input to avoid server errors [OK]

Hint: Validate empty input to prevent server errors [OK]

Common Mistakes:

• Ignoring empty input causing crashes
• Changing HTTP method incorrectly
• Skipping JSON parsing

5. You want to design a batch create endpoint that returns the ID of each created item and reports errors per item without failing the whole batch. Which response design is best?

hard

A. {"results": [{"id": 1, "status": "created"}, {"error": "Invalid name", "status": "failed"}]}

B. {"error": "Batch failed", "status": 400}

C. [{"id": 1}, {"id": 2}]

D. {"message": "All items created successfully"}

Solution

1. Step 1: Understand partial success reporting

   To report success or failure per item, response must include status and details for each.

2. Step 2: Match response format to requirements

   {"results": [{"id": 1, "status": "created"}, {"error": "Invalid name", "status": "failed"}]} provides per-item status and error messages, allowing partial success.

3. Final Answer:

   {"results": [{"id": 1, "status": "created"}, {"error": "Invalid name", "status": "failed"}]} -> Option A

4. Quick Check:

   Per-item status in response enables partial success [OK]

Hint: Return per-item status and errors in response [OK]

Common Mistakes:

• Failing whole batch on one error
• Returning only success without error info
• Using generic messages without details