easyDSA

What is the CASE expression?

Q: What is the CASE expression?

**CASE** is SQL's conditional: `CASE WHEN cond THEN a ELSE b END`. Use it in SELECT for derived columns, in ORDER BY for custom ordering, or with aggregates for conditional/pivot-style counts (`SUM(CASE WHEN ... THEN 1 ELSE 0 END)`).

1.0k views

Understand the problem

Explain CASE.

case

Attempt it yourself

Sketch your approach before reading the solution — that's what interviews test.

Nudge consolestandby

Stuck? Beam a request up — the console returns a conceptual nudge that guides your logic without spoiling the implementation.

Study the solution

CASE is SQL's conditional: CASE WHEN cond THEN a ELSE b END. Use it in SELECT for derived columns, in ORDER BY for custom ordering, or with aggregates for conditional/pivot-style counts (SUM(CASE WHEN ... THEN 1 ELSE 0 END)).

Solution ready — 2 min read

Classified // press E to declassify

Run the code

SQLCASE Playground

Join the discussion

Discussion (0)

No responses yet. Be the first to share what you think.

Transmission complete // awaiting log

KEEP THE
STREAK ALIVE.

Dossier 5 of 70 decoded in the SQL track. One more won't hurt.

Back to track

Next up→

What is the difference between WHERE and HAVING?

Continue