Delete specified rows
The WHERE clause in a DELETE statement has the same form
as the WHERE clause in a SELECT statement. You can use it to designate
exactly which row or rows should be deleted. You can delete a customer
with a specific customer number, as the following example shows:
DELETE FROM customer WHERE customer_num = 175;
In this example, because the customer_num column has a unique constraint, you can ensure that no more than one row is deleted.