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

PI()()

PI()()

  • PI() is a MySQL math function: PI() is 3.14159… no arguments. Use it in SELECT, e.g. SELECT PI() FROM students;
  • These functions do not change stored marks unless you UPDATE. NULL in, NULL out for most of them.
  • Trap: mixing PI 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: PI()(): create two demo rows, then SELECT qty >= 2 ordered. Say which labels come back.

Technical Interview Tip: Explain PI with one number. PI() is 3.14159… no arguments.

Code Examples for PI()()

PI()() — sample query

-- PI()()
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;

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

How to Explain PI()() to an Interviewer

What is PI?

PI() is 3.14159… no arguments Used in SELECT