DELETE usage and examples

Overview

DELETE removes rows that satisfy WHERE; without WHERE it removes every row while keeping the table structure. Before execution, run SELECT with the same predicate, check related tables, foreign-key behavior, and expected row count, then use a reversible transaction. Large deletes can create long transactions and locks, so consider batching and archival needs.

Basic syntax

DELETE FROM orders WHERE id = 1;

Examples

DELETE example

Delete order id 1 with an explicit primary-key predicate so no other sample rows are affected.

Sample table

Table：orders

orders
id
1
2
3
4

Run result

orders
id
2
3
4

Common issues

Why run SELECT before changing data?

Checking the same WHERE predicate reveals an overly broad or missing condition before rows are changed.

What happens without WHERE?

UPDATE changes every row and DELETE removes every row, so verify scope before production use.

How can I reduce operational risk?

Use a transaction, inspect affected rows, commit only after verification, and keep recoverable backups for critical data.

Keep reading

INSERT INTO UPDATE

DELETE