DELETE for removing resources in Rest API - Step-by-Step Execution

Concept Flow - DELETE for removing resources

Client sends DELETE request

↓

Server receives request

↓

Server checks resource exists

↓

Server deletes resource

↓

Server sends 200 OK or 204 No Content

↓

Client receives confirmation

The client sends a DELETE request to remove a resource. The server checks if the resource exists, deletes it if found, and sends a confirmation response.

Execution Sample

Rest API

DELETE /items/123 HTTP/1.1
Host: example.com

Response:
HTTP/1.1 204 No Content

Client requests deletion of item 123; server confirms deletion with 204 No Content.

Execution Table

Step	Action	Resource Exists?	Server Response	Client Outcome
1	Client sends DELETE /items/123	Unknown	Waiting	Waiting
2	Server receives DELETE request	Check resource 123	Checking	Waiting
3	Resource 123 found	Yes	Delete resource	Waiting
4	Resource 123 deleted	Yes	Send 204 No Content	Waiting
5	Client receives response	N/A	204 No Content	Deletion confirmed
6	Client tries to GET /items/123	Check resource 123	Not found	Resource missing

💡 Resource 123 deleted successfully; server responds with 204 No Content.

Variable Tracker

Variable	Start	After Step 2	After Step 3	After Step 4	Final
resource_exists	Unknown	Checking	Yes	Deleted	Deleted
server_response	None	Waiting	Deleting	204 No Content	204 No Content
client_state	Idle	Waiting	Waiting	Waiting	Deletion confirmed

Key Moments - 3 Insights

Why does the server send 204 No Content instead of 200 OK?

204 No Content means the deletion was successful but there is no message body to send back. See execution_table row 4 where server sends 204 after deleting.

What happens if the resource does not exist?

The server sends a 404 Not Found response. This is shown in the concept_flow where if resource check is No, server sends 404.

Does the client get any data back after deletion?

No, the 204 response has no content. The client only gets confirmation the resource was deleted, as shown in execution_table row 5.

Visual Quiz - 3 Questions

Look at the execution_table, what is the server response immediately after deleting the resource?

A 404 Not Found

B 200 OK

C 204 No Content

D 500 Internal Server Error

💡 Hint

Check execution_table row 4 under 'Server Response'

At which step does the server confirm the resource exists before deleting?

A Step 1

B Step 3

C Step 2

D Step 5

💡 Hint

Look at execution_table row 3 where resource existence is confirmed

If the resource did not exist, what would the server response be?

A 404 Not Found

B 200 OK

C 204 No Content

D 301 Moved Permanently

💡 Hint

Refer to concept_flow branch when resource check is No

Concept Snapshot

DELETE request removes a resource at the server.
Client sends DELETE /resource/id.
Server checks if resource exists.
If yes, deletes and sends 204 No Content.
If no, sends 404 Not Found.
Client receives confirmation with no content.

Full Transcript

When a client wants to remove something on a server, it sends a DELETE request with the resource's address. The server looks to see if that resource exists. If it does, the server deletes it and sends back a 204 No Content response, meaning success but no extra data. If the resource is missing, the server replies with 404 Not Found. The client then knows if the deletion worked or if the resource was not there. This process helps keep data clean and confirms actions clearly.

Practice

1. What is the main purpose of the HTTP DELETE method in REST APIs?

easy

A. To remove a resource identified by a URL

B. To create a new resource on the server

C. To update an existing resource

D. To retrieve data from the server

Solution

1. Step 1: Understand HTTP methods

   HTTP methods define actions on resources. DELETE is specifically for removal.

2. Step 2: Identify DELETE's role

   DELETE removes the resource at the given URL, unlike POST (create), PUT/PATCH (update), or GET (retrieve).

3. Final Answer:

   To remove a resource identified by a URL -> Option A

4. Quick Check:

   DELETE = remove resource [OK]

Hint: DELETE always removes resource at the URL, no body needed [OK]

Common Mistakes:

• Confusing DELETE with GET or POST
• Thinking DELETE requires a request body
• Assuming DELETE creates or updates data

2. Which of the following is the correct syntax to send a DELETE request to remove a user with ID 123 using curl?

easy

A. curl -X GET https://api.example.com/users/123

B. curl -X PUT https://api.example.com/users/123

C. curl -X POST https://api.example.com/users/123

D. curl -X DELETE https://api.example.com/users/123

Solution

1. Step 1: Identify HTTP method for deletion

   DELETE method is used to remove resources, so -X DELETE is correct.

2. Step 2: Check URL and method usage

   The URL targets user 123, and curl uses -X to specify method. So, curl -X DELETE URL is correct.

3. Final Answer:

   curl -X DELETE https://api.example.com/users/123 -> Option D

4. Quick Check:

   curl DELETE syntax = curl -X DELETE URL [OK]

Hint: Use curl -X DELETE followed by resource URL [OK]

Common Mistakes:

• Using GET or POST instead of DELETE
• Omitting the -X flag for method
• Using PUT which is for updates

3. Given this Python code using requests library:

import requests
response = requests.delete('https://api.example.com/items/45')
print(response.status_code)

What will be printed if the item was successfully deleted?

medium

A. 201

B. 404

C. 200

D. 500

Solution

1. Step 1: Understand HTTP status codes for DELETE

   Successful DELETE usually returns 200 (OK) or 204 (No Content). 200 means success with response body.

2. Step 2: Check options for success code

   Among options, 200 indicates success. 404 means not found, 500 server error, 201 created (not for DELETE).

3. Final Answer:

   200 -> Option C

4. Quick Check:

   DELETE success = 200 OK [OK]

Hint: Successful DELETE usually returns 200 or 204 status code [OK]

Common Mistakes:

• Confusing 201 (created) with success for DELETE
• Assuming 404 means success
• Ignoring status code meanings

4. Consider this JavaScript fetch code to delete a post:

fetch('https://api.example.com/posts/10', {
  method: 'DELETE',
  body: JSON.stringify({ id: 10 })
})
.then(res => res.status)
.then(console.log)

What is the main issue with this code?

medium

A. The URL is incorrect

B. DELETE requests should not have a body

C. The method should be GET

D. Missing headers for JSON content

Solution

1. Step 1: Understand DELETE request body rules

   DELETE usually does not require a request body; many servers ignore or reject it.

2. Step 2: Identify the problem in code

   The code sends a JSON body with DELETE, which is often unnecessary and may cause errors.

3. Final Answer:

   DELETE requests should not have a body -> Option B

4. Quick Check:

   DELETE usually no body [OK]

Hint: Avoid sending body with DELETE requests [OK]

Common Mistakes:

• Adding unnecessary body to DELETE
• Confusing method with GET or POST
• Forgetting to check server docs for DELETE body support

5. You want to delete multiple resources in one request using REST API. Which approach is best practice?

hard

A. Send multiple DELETE requests, one per resource URL

B. Send a single DELETE request with a JSON array body listing IDs

C. Use POST method with action=delete and list of IDs in body

D. Use GET method with query parameters to delete resources

Solution

1. Step 1: Understand REST principles for DELETE

   DELETE targets a single resource URL. Bulk delete is not standardized and often unsupported.

2. Step 2: Evaluate options for bulk deletion

   Sending multiple DELETE requests (one per resource) is standard and reliable. Other methods misuse HTTP verbs or semantics.

3. Final Answer:

   Send multiple DELETE requests, one per resource URL -> Option A

4. Quick Check:

   One DELETE per resource URL [OK]

Hint: Delete resources one by one with separate DELETE requests [OK]

Common Mistakes:

• Trying to send bulk delete in one DELETE with body
• Using POST or GET to delete resources
• Assuming server supports bulk delete by default