SQL · Theory

CURDATE()

Theory

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CURDATE()

If you can teach CURDATE() using a CURDATE dry-run, you know it. If you only know the heading, you don’t.

CURDATE() on the board — one CURDATE step Sara can write from memory. Then say what a CURDATE dry-run looks like after.

Without CURDATE(), a campus project gets messy and a CURDATE dry-run is hard to trust.

CURDATE() shows up in a campus project. Name a CURDATE dry-run, not “a real-world scenario”.

Don’t do this with CURDATE() — copy-pasting CURDATE without a dry-run. Interviewers spot it in ten seconds.

Place CURDATE() next to nearby SQL work — one CURDATE step Sara can write from memory is the link.

Viva for CURDATE(): what it is → one CURDATE step Sara can write from memory → the mistake (copy-pasting CURDATE without a dry-run).

Exam tip

Board: a CURDATE dry-run. Dry-run CURDATE(). Name the trap: copy-pasting CURDATE without a dry-run.

CURDATE() — sample query

-- CURDATE()
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;

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

Short notes

DefCURDATE() — Sara uses it for a CURDATE dry-run in a campus project.
RuleCURDATE() → one CURDATE step Sara can write from memory.
RememberCURDATE() + the query planner (a campus project).
UseCURDATE() in a campus project (a CURDATE dry-run).
TrapCURDATE() — copy-pasting CURDATE without a dry-run.
ExCURDATE() → a CURDATE dry-run.

-- CURDATE() 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;

CURDATE()

CURDATE() — sample query

Short notes

Questions

CURDATE()

CURDATE() — sample query

Short notes

Questions