DELETE FROM celebs WHERE twitter_handle IS NULL;
DELETE FROM statement deletes one or more rows from a table. You can use the statement when you want to delete existing records.
DELETE FROM is a clause that lets you delete rows from a table.
celebs is the name of the table we want to delete rows from.
WHERE is a clause that lets you select which rows you want to delete. Here we want to delete all of the rows where the twitter_handle column
IS NULL is a condition in SQL that returns true when the value is
NULL and false otherwise.