SQL · Theory

Sequence

Theory

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Sequence

Don’t start Sequence with jargon. Start with Rohit walking through Sequence. That is the whole point.

Sequence order — meaning → one Sequence step Rohit can write from memory → one limit. Dumping ten features helps nobody.

Sequence exists so Rohit can keep Rohit walking through Sequence correct in a small live site.

Sequence shows up in a small live site. Name Rohit walking through Sequence, not “a real-world scenario”.

Sequence miss — skipping the failure case for Sequence. Fix it before you talk about advanced SQL.

After Sequence, Rohit should still remember skipping the failure case for Sequence.

One breath for Sequence, then Rohit walking through Sequence, then skipping the failure case for Sequence. Sit down.

Exam tip

Say Sequence in one breath, then one Sequence step Rohit can write from memory, then skipping the failure case for Sequence.

Sequence — sample query

-- Sequence
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;

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

Short notes

DefSequence — Rohit uses it for Rohit walking through Sequence in a small live site.
RuleSequence → one Sequence step Rohit can write from memory.
RememberSequence + an index (a small live site).
UseSequence in a small live site (Rohit walking through Sequence).
TrapSequence — skipping the failure case for Sequence.
ExSequence → Rohit walking through Sequence.

-- Sequence 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;

Sequence

Sequence — sample query

Short notes

Questions

Sequence

Sequence — sample query

Short notes

Questions