SQL · Theory

DAYOFMONTH()

Theory

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DAYOFMONTH()

Priya only reaches for DAYOFMONTH() when Priya walking through DAYOFMONTH has to stay correct in lab hour.

DAYOFMONTH() order: meaning → one DAYOFMONTH step Priya can write from memory → one limit. Dumping ten features helps nobody.

DAYOFMONTH() exists so Priya can keep Priya walking through DAYOFMONTH correct in lab hour.

Use DAYOFMONTH() when Priya walking through DAYOFMONTH must stay clear. If a simpler SQL step works, use that instead.

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

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

One breath for DAYOFMONTH(), then Priya walking through DAYOFMONTH, then only reciting the name of DAYOFMONTH. Sit down.

Exam tip

For DAYOFMONTH(): definition + lab hour + one failure.

DAYOFMONTH() — sample query

-- DAYOFMONTH()
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;

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

Short notes

DefDAYOFMONTH() — Priya uses it for Priya walking through DAYOFMONTH in lab hour.
RuleDAYOFMONTH() → one DAYOFMONTH step Priya can write from memory.
RememberDAYOFMONTH() + InnoDB (lab hour).
UseDAYOFMONTH() in lab hour (Priya walking through DAYOFMONTH).
TrapDAYOFMONTH() — only reciting the name of DAYOFMONTH.
ExDAYOFMONTH() → Priya walking through DAYOFMONTH.

-- DAYOFMONTH() 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;

DAYOFMONTH()

DAYOFMONTH() — sample query

Short notes

Questions

DAYOFMONTH()

DAYOFMONTH() — sample query

Short notes

Questions