SQRT()() — SQL Technical Interview Questions & Answers

SQRT()()

SQRT()()

  • SQRT() is a MySQL math function: square root. SQRT(9) is 3. Use it in SELECT, e.g. SELECT SQRT(marks) FROM students;
  • These functions do not change stored marks unless you UPDATE. NULL in, NULL out for most of them.
  • Trap: mixing SQRT with TRUNCATE TABLE (different word). Trap: maths on VARCHAR without CAST.
  • In a viva, one numeric example beats listing twenty functions.
  • On the example next to this theory: SQRT()(): create two demo rows, then SELECT qty >= 2 ordered. Say which labels come back.

Technical Interview Tip: Explain SQRT with one number. square root. SQRT(9) is 3.

Code Examples for SQRT()()

SQRT()() — sample query

-- SQRT()()
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;

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

How to Explain SQRT()() to an Interviewer

What is SQRT?

square root. SQRT(9) is 3 Used in SELECT