SQL - DELETE in SQL

What Is DELETE in SQL?

The DELETE statement in SQL is used to remove one or more rows from a table. It is part of the Data Manipulation Language (DML) and permanently deletes data (unless you're using transactions and rollbacks).

Basic Syntax

DELETE FROM table_name
WHERE condition;

• table_name: the name of the table you want to delete data from.

• condition: specifies which rows to delete.

Important: Without WHERE, All Rows Are Deleted!

DELETE FROM employees;  -- deletes ALL rows in the table!

Example: Delete a Specific Row

Table: employees

DELETE FROM employees
WHERE id = 2;

• Deletes the row where id = 2 (Bob).

Delete Based on a Condition

DELETE FROM employees
WHERE department = 'HR';

• Deletes all employees in the HR department.

Delete Using a Subquery

DELETE FROM employees
WHERE id IN (
  SELECT employee_id FROM resignations
);

• Deletes employees who have resigned (based on another table).

DELETE vs TRUNCATE vs DROP