last() — SQL Technical Interview Questions & Answers

last()

last()

  • MAX(marks) highest value. Topper query: ORDER BY marks DESC LIMIT 1 or WHERE marks = (SELECT MAX(marks) FROM students). The subquery form keeps ties.
  • LIMIT 1 hides ties. Say that in the interview.
  • Trap: MAX without mentioning ties.
  • On the example next to this theory: last(): create two demo rows, then SELECT qty >= 2 ordered. Say which labels come back.

Technical Interview Tip: MAX(marks). Ties: WHERE marks = (SELECT MAX(marks) FROM students).

Code Examples for last()

last() — sample query

-- last()
CREATE TABLE demo (
  id INTEGER PRIMARY KEY,
  label TEXT NOT NULL,
  qty INTEGER DEFAULT 0
);
INSERT INTO demo (id, label, qty) VALUES
  (1, 'alpha', 2),
  (2, 'beta', 5);
SELECT label, qty FROM demo WHERE qty >= 2 ORDER BY qty DESC;

last(): create two demo rows, then SELECT qty >= 2 ordered. Say which labels come back.

How to Explain last() to an Interviewer

All toppers, not one?

WHERE marks = (SELECT MAX(marks) FROM students)