SQL · Theory

ATAN()()

Theory

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ATAN()()

ATAN()() (math) is a SQL idea you prove with Riya walking through ATAN math, not with a slogan.

ATAN()() (math) on the board: one ATAN math step Riya can write from memory. Then say what Riya walking through ATAN math looks like after.

ATAN()() (math) exists so Riya can keep Riya walking through ATAN math correct in a campus project.

ATAN()() (math) shows up in a campus project. Name Riya walking through ATAN math, not “a real-world scenario”.

ATAN()() (math) miss — skipping the failure case for ATAN math. Fix it before you talk about advanced SQL.

After ATAN()() (math), Riya should still remember skipping the failure case for ATAN math.

One breath for ATAN()() (math), then Riya walking through ATAN math, then skipping the failure case for ATAN math. Sit down.

Exam tip

Board: Riya walking through ATAN math. Dry-run ATAN()() (math). Name the trap: skipping the failure case for ATAN math.

ATAN()() — sample query

-- ATAN()()
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;

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

Short notes

DefATAN()() (math) — Riya uses it for Riya walking through ATAN math in a campus project.
RuleATAN()() (math) → one ATAN math step Riya can write from memory.
RememberATAN()() (math) + InnoDB (a campus project).
UseATAN()() (math) in a campus project (Riya walking through ATAN math).
TrapATAN()() (math) — skipping the failure case for ATAN math.
ExATAN()() (math) → Riya walking through ATAN math.

-- ATAN()() 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;

ATAN()()

ATAN()() — sample query

Short notes

Questions

ATAN()()

ATAN()() — sample query

Short notes

Questions