SQL · Theory

ADDDATE()

Theory

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ADDDATE()

ADDDATE() is simple if you keep it on paper. Ananya uses it for Ananya walking through ADDDATE in a small live site.

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

ADDDATE() exists so Ananya can keep Ananya walking through ADDDATE correct in a small live site.

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

ADDDATE() miss — copy-pasting ADDDATE without a dry-run. Fix it before you talk about advanced SQL.

ADDDATE() is not a lonely heading. Ananya ties it to Ananya walking through ADDDATE.

One breath for ADDDATE(), then Ananya walking through ADDDATE, then copy-pasting ADDDATE without a dry-run. Sit down.

Exam tip

For ADDDATE(): definition + a small live site + one failure.

ADDDATE() — sample query

-- ADDDATE()
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;

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

Short notes

DefADDDATE() — Ananya uses it for Ananya walking through ADDDATE in a small live site.
RuleADDDATE() → one ADDDATE step Ananya can write from memory.
RememberADDDATE() + an index (a small live site).
UseADDDATE() in a small live site (Ananya walking through ADDDATE).
TrapADDDATE() — copy-pasting ADDDATE without a dry-run.
ExADDDATE() → Ananya walking through ADDDATE.

-- ADDDATE() 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;

ADDDATE()

ADDDATE() — sample query

Short notes

Questions

ADDDATE()

ADDDATE() — sample query

Short notes

Questions