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Lesson 4 — UPDATE & DELETE
DELETE: remove rows carefully
DELETE FROM table WHERE condition removes the matching rows. cursor.rowcount tells you how many were removed. Like UPDATE, a DELETE without WHERE wipes the whole table. A safe habit: run the same WHERE as a SELECT first to see what would go.
SELECT COUNT(*) FROM carts WHERE abandoned = 1 -- check
DELETE FROM carts WHERE abandoned = 1 -- then delete
Why it matters: cleaning old data is routine, and "forgot the WHERE" is a famous way to lose a production table.
Want it another way?
Task
Write the DELETE that removes only expired sessions. Expected: 2 deleted, 2 left.
Run your code — when the output matches the task, you will see a green check. Then mark the lesson complete.
Test your knowledge
Test your knowledgeA quick 3-question quiz on this lesson — instant feedback.