Delete all Data from Table MySQL — SQL Technical Interview Questions & Answers

Delete all Data from Table MySQL

Delete all Data from Table MySQL

  • TRUNCATE TABLE students; deletes every row fast and resets AUTO_INCREMENT. The table structure stays. It is DDL in MySQL — you usually cannot ROLLBACK a truncate like a DELETE in a transaction (engine/version details aside: treat TRUNCATE as ‘gone’).
  • DELETE FROM students; also removes all rows but logs each row, fires DELETE triggers, and can be rolled back in a transaction. Use DELETE when you need WHERE, triggers, or rollback. Use TRUNCATE when you want an empty table quickly in practice.
  • Trap: TRUNCATE on a table that other tables reference with FOREIGN KEY — InnoDB may refuse. Trap: thinking TRUNCATE is the same as DROP TABLE (DROP removes the table itself).
  • On the example next to this theory: Delete all Data from Table MySQL — dELETE removes matching rows. TRUNCATE clears a whole table faster (MySQL).

Technical Interview Tip: TRUNCATE = empty table, keep columns. DELETE = can WHERE and rollback.

Code Examples for Delete all Data from Table MySQL

Delete all Data from Table MySQL — sample query

CREATE TABLE tags (id INTEGER PRIMARY KEY, label TEXT);
INSERT INTO tags VALUES (1, 'old'), (2, 'keep');
DELETE FROM tags WHERE label = 'old';
SELECT * FROM tags;

Delete all Data from Table MySQL — dELETE removes matching rows. TRUNCATE clears a whole table faster (MySQL).

How to Explain Delete all Data from Table MySQL to an Interviewer

TRUNCATE vs DELETE all rows?

TRUNCATE is faster, resets AI DELETE can rollback and use WHERE

TRUNCATE vs DROP?

TRUNCATE keeps the table DROP removes the table