Batch update patterns in Rest API - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a batch update in REST APIs?

A batch update is a way to send multiple update requests in a single API call, reducing the number of network requests and improving efficiency.

beginner

Name two common HTTP methods used for batch updates.

PATCH and PUT are commonly used for batch updates. PATCH is for partial updates, while PUT usually replaces the entire resource.

intermediate

What is the advantage of using a single endpoint for batch updates?

Using a single endpoint for batch updates reduces network overhead, simplifies client code, and can ensure atomicity if supported by the server.

intermediate

Explain the difference between atomic and non-atomic batch updates.

Atomic batch updates mean all updates succeed or all fail together, ensuring consistency. Non-atomic updates may partially succeed, requiring error handling for partial failures.

beginner

What is a common JSON structure for sending batch updates in REST APIs?

A common structure is an array of objects, each containing the resource ID and the fields to update, for example: [{"id":1, "field":"value"}, {"id":2, "field":"value2"}].

Which HTTP method is typically used for partial batch updates in REST APIs?

A PATCH

B GET

C POST

D DELETE

PATCH is used for partial updates, making it suitable for batch updates where only some fields change.

What is a key benefit of batch updating resources in one API call?

A Increases server load

B Reduces network requests

C Requires multiple endpoints

D Slows down response time

Batch updates reduce the number of network requests, improving efficiency.

In a batch update, what does atomicity ensure?

A Updates are ignored

B Updates happen one by one

C Partial updates are allowed

D All updates succeed or none do

Atomicity means either all updates succeed together or all fail, preventing partial changes.

Which JSON format is commonly used to send batch updates?

A A boolean value

B A single string

C An array of update objects

D A number

Batch updates are usually sent as an array of objects, each describing an update.

If a batch update partially fails, what is a common approach?

A Return detailed error info for failed items

B Ignore errors silently

C Delete all resources

D Restart the server

APIs often return detailed errors for failed updates so clients can handle them properly.

Describe how batch update patterns improve REST API efficiency and what challenges they might introduce.

Think about how sending many updates at once affects speed and complexity.

Explain the difference between using PATCH and PUT methods in batch updates.

Consider how much data you want to change in each resource.

Practice

1. What is the main advantage of using batch update patterns in REST APIs?

easy

A. They only work with GET requests.

B. They allow updating multiple items with a single request, saving time.

C. They require sending separate requests for each item.

D. They increase the number of requests to the server.

Solution

1. Step 1: Understand batch update purpose

   Batch update patterns let you update many items at once instead of one by one.

2. Step 2: Identify the benefit

   This reduces the number of requests and saves time and server resources.

3. Final Answer:

   They allow updating multiple items with a single request, saving time. -> Option B

4. Quick Check:

   Batch update = single request for many items [OK]

Hint: Batch updates reduce requests by combining many updates [OK]

Common Mistakes:

• Thinking batch updates increase requests
• Confusing batch update with single item update
• Assuming batch updates use GET method

2. Which HTTP method is most appropriate for batch updates in REST APIs?

easy

A. GET

B. POST

C. PATCH

D. DELETE

Solution

1. Step 1: Recall HTTP methods for updates

   PATCH is used to partially update resources, suitable for batch updates.

2. Step 2: Eliminate other methods

   GET retrieves data, POST creates new data, DELETE removes data, so they are not best for batch updates.

3. Final Answer:

   PATCH -> Option C

4. Quick Check:

   Batch update uses PATCH method [OK]

Hint: Use PATCH for partial or batch updates [OK]

Common Mistakes:

• Using GET for updates
• Confusing POST with update method
• Using DELETE instead of PATCH

3. Given this JSON payload sent in a PATCH request for batch update:

[{"id":1,"status":"done"},{"id":2,"status":"pending"}]

What does this payload represent?

medium

A. Retrieve items with id 1 and 2.

B. Create two new items with given ids and statuses.

C. Delete items with id 1 and 2.

D. Update status of items with id 1 and 2 to 'done' and 'pending' respectively.

Solution

1. Step 1: Analyze JSON payload

   The payload is an array of objects each with 'id' and 'status' fields, indicating updates.

2. Step 2: Understand PATCH semantics

   PATCH updates existing items partially, so this changes status fields for items with id 1 and 2.

3. Final Answer:

   Update status of items with id 1 and 2 to 'done' and 'pending' respectively. -> Option D

4. Quick Check:

   PATCH with array updates multiple items [OK]

Hint: PATCH with array updates multiple items by id [OK]

Common Mistakes:

• Thinking PATCH creates new items
• Confusing update with delete
• Assuming it retrieves data

4. You send this PATCH request payload to update multiple items:

[{"id":1,"status":"done"}, {"status":"pending"}]

What is the likely problem?

medium

A. Missing 'id' in second object causes update failure or error.

B. The payload is valid and will update all items.

C. Using PATCH instead of POST causes syntax error.

D. The array should be empty for batch updates.

Solution

1. Step 1: Check each object in payload

   The second object lacks 'id', so the server cannot identify which item to update.

2. Step 2: Understand update requirements

   Each update must specify the item to update, usually by 'id'. Missing it causes failure or error.

3. Final Answer:

   Missing 'id' in second object causes update failure or error. -> Option A

4. Quick Check:

   Each update needs an identifier like 'id' [OK]

Hint: Every update object must include an identifier like 'id' [OK]

Common Mistakes:

• Assuming missing 'id' is allowed
• Confusing PATCH with POST errors
• Thinking empty arrays are required

5. You want to batch update user roles but only for users currently active. Which pattern best fits this requirement?

hard

A. Send a PATCH request with an array of user objects filtered to active users only.

B. Send separate PATCH requests for all users regardless of status.

C. Use GET request to update roles for active users.

D. Send a DELETE request with active users to update roles.

Solution

1. Step 1: Identify filtering need

   Only active users should be updated, so filter users before sending batch update.

2. Step 2: Choose correct method and payload

   PATCH with an array of filtered user objects updates roles efficiently in one request.

3. Final Answer:

   Send a PATCH request with an array of user objects filtered to active users only. -> Option A

4. Quick Check:

   Filter then batch update with PATCH [OK]

Hint: Filter data first, then batch update with PATCH [OK]

Common Mistakes:

• Sending updates for all users without filtering
• Using GET or DELETE for updates
• Sending multiple separate requests instead of batch