SQL - DELETE

So far we’ve learnt how to select data from a database table and how to insert and update data into a database table. Now it’s time to learn how to remove data from a database. Here comes the DELETE statement!

The DELETE command has the following generic SQL syntax:

DELETE FROM Table1 WHERE Some_Column = Some_Value

If you skip the WHERE clause when executing DELETE expression, then all the data in the specified table will be deleted. The following SQL statement will delete all the data from our Customers table and we’ll end up with completely empty table:

DELETE FROM Table1

If you specify a WHERE clause in your DELETE statement, only the table rows satisfying the WHERE criteria will be deleted:

DELETE FROM Customers WHERE LastName = 'Smith'

The SQL query above will delete all database rows having LastName 'Smith' and will leave the Customers table in the following state:

FirstName	LastName	Email	DOB	Phone
Steven	Goldfish	goldfish@fishhere.net	4/4/1974	323 455-4545
Paula	Brown	pb@herowndomain.org	5/24/1978	416 323-3232