SQL · Theory

CURRENT_DATE()

Theory

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CURRENT_DATE()

If you can teach CURRENT_DATE() using Meera walking through CURRENT_DATE, you know it. If you only know the heading, you don’t.

Do CURRENT_DATE() once by hand. one CURRENT_DATE step Meera can write from memory. Change one input. Say the new result out loud.

Skip CURRENT_DATE() and only reciting the name of CURRENT_DATE shows up in a small live site.

Meera ships CURRENT_DATE() in a small live site. That is the use case worth saying.

If Meera walking through CURRENT_DATE breaks under CURRENT_DATE(), check only reciting the name of CURRENT_DATE first.

After CURRENT_DATE(), Meera should still remember only reciting the name of CURRENT_DATE.

Close CURRENT_DATE() with: “If I skip it, Meera walking through CURRENT_DATE goes wrong like this: only reciting the name of CURRENT_DATE.”

Exam tip

Board: Meera walking through CURRENT_DATE. Dry-run CURRENT_DATE(). Name the trap: only reciting the name of CURRENT_DATE.

CURRENT_DATE() — sample query

-- CURRENT_DATE()
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;

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

Short notes

DefCURRENT_DATE() — Meera uses it for Meera walking through CURRENT_DATE in a small live site.
RuleCURRENT_DATE() → one CURRENT_DATE step Meera can write from memory.
RememberCURRENT_DATE() + an index (a small live site).
UseCURRENT_DATE() in a small live site (Meera walking through CURRENT_DATE).
TrapCURRENT_DATE() — only reciting the name of CURRENT_DATE.
ExCURRENT_DATE() → Meera walking through CURRENT_DATE.

-- CURRENT_DATE() 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;

CURRENT_DATE()

CURRENT_DATE() — sample query

Short notes

Questions

CURRENT_DATE()

CURRENT_DATE() — sample query

Short notes

Questions