Batch delete patterns in Rest API - Step-by-Step Execution

Concept Flow - Batch delete patterns

Client sends batch delete request

↓

Server receives request with multiple IDs

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Server validates IDs

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Delete items

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Return success response with status for each item

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Client processes response

The client sends a request to delete multiple items at once. The server checks the IDs, deletes valid ones, and returns a detailed response.

Execution Sample

Rest API

DELETE /items?ids=1,2,3,4

Response:
{
  "deleted": [1,2,3],
  "not_found": [4]
}

This example shows a batch delete request with IDs 1 to 4, where item 4 was not found.

Execution Table

Step	Action	Input	Validation Result	Delete Result	Response Output
1	Receive request	ids=1,2,3,4	IDs parsed	-	-
2	Validate ID 1	1	Valid	Deleted	-
3	Validate ID 2	2	Valid	Deleted	-
4	Validate ID 3	3	Valid	Deleted	-
5	Validate ID 4	4	Not found	Not deleted	-
6	Compile response	-	-	-	{"deleted": [1,2,3], "not_found": [4]}
7	Send response	-	-	-	Response sent to client

💡 All IDs processed; response sent with deletion status.

Variable Tracker

Variable	Start	After 1	After 2	After 3	After 4	Final
ids_to_delete	[1,2,3,4]	[2,3,4]	[3,4]	[4]	[]	[]
deleted_ids	[]	[1]	[1,2]	[1,2,3]	[1,2,3]	[1,2,3]
not_found_ids	[]	[]	[]	[]	[4]	[4]

Key Moments - 2 Insights

Why does the server return some IDs as 'not_found' instead of deleting them?

Because those IDs do not exist in the database. The execution_table rows 5 and 6 show that ID 4 was validated as 'Not found' and was not deleted.

What happens if one of the IDs is invalid or malformed?

The server would reject the entire request or return an error for that ID. This is hinted in the concept_flow where validation can lead to an error response if IDs are invalid.

Visual Quiz - 3 Questions

Look at the execution_table, which IDs were successfully deleted?

A [1, 2, 3]

B [2, 3, 4]

C [4]

D None

💡 Hint

Check the 'Delete Result' column in rows 2 to 4.

At which step does the server identify an ID that cannot be deleted?

A Step 3

B Step 6

C Step 5

D Step 7

💡 Hint

Look at the 'Validation Result' column for the step where 'Not found' appears.

If the client sent IDs '1,2,5' and ID 5 does not exist, how would the 'not_found_ids' variable change?

A It would be empty

B It would include 5

C It would include 1 and 2

D It would include all IDs

💡 Hint

Refer to variable_tracker row for 'not_found_ids' and how it tracks missing IDs.

Concept Snapshot

Batch delete pattern:
- Client sends DELETE request with multiple IDs
- Server parses and validates each ID
- Deletes existing items, skips missing ones
- Returns JSON with 'deleted' and 'not_found' lists
- Helps efficiently remove many items in one call

Full Transcript

Batch delete patterns let clients remove many items in one request. The client sends a DELETE request with a list of IDs. The server checks each ID: if it exists, it deletes it; if not, it notes it as not found. The server then sends back a response showing which IDs were deleted and which were missing. This saves time and network calls compared to deleting items one by one.