Show Columns — SQL Technical Interview Questions & Answers

Show Columns

Show Columns

  • SHOW COLUMNS FROM students; is DESCRIBE in another spelling. SHOW COLUMNS FROM students LIKE 'm%'; filters. information_schema.COLUMNS is the joinable catalog.
  • Trap: memorising both SHOW COLUMNS and DESC as ‘different concepts’. They answer the same question.
  • On the example next to this theory: Show Columns: create two demo rows, then SELECT qty >= 2 ordered. Say which labels come back.

Technical Interview Tip: SHOW COLUMNS FROM students; = DESCRIBE students;

Code Examples for Show Columns

Show Columns — sample query

-- Show Columns
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;

Show Columns: create two demo rows, then SELECT qty >= 2 ordered. Say which labels come back.

How to Explain Show Columns to an Interviewer

SHOW COLUMNS vs DESCRIBE?

Same idea Column names, types, keys