DELETE Statements

Syntax

DELETE FROM table_name
[WHERE condition]
[;]

The DELETE statement removes rows from a table based on an optional WHERE clause.

Basic Example

-- Remove all rows where the status is 'inactive'
DELETE FROM Employees
WHERE Status = 'inactive';

Deleting All Rows

-- Delete every row from the table (use with caution!)
DELETE FROM Orders;

Without a WHERE clause, every row is removed but the table structure remains.

Using Joins

-- Delete orders that belong to customers in a specific region
DELETE o
FROM Orders o
JOIN Customers c ON o.CustomerID = c.CustomerID
WHERE c.Region = 'West';

Best Practices

• Always back up data before performing bulk deletes.
• Test the WHERE clause with a SELECT first.
• Consider using transactions to allow rollback.
• Index columns used in the WHERE clause for performance.