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NOT

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NOT

NOT is a SQL idea you prove with a NOT dry-run, not with a slogan.

Do NOT once by hand. one NOT step Farhan can write from memory. Change one input. Say the new result out loud.

NOT exists so Farhan can keep a NOT dry-run correct in lab hour.

Farhan ships NOT in lab hour. That is the use case worth saying.

Don’t do this with NOT — copy-pasting NOT without a dry-run. Interviewers spot it in ten seconds.

After NOT, Farhan should still remember copy-pasting NOT without a dry-run.

Close NOT with — “If I skip it, a NOT dry-run goes wrong like this: copy-pasting NOT without a dry-run.”

Exam tip

For NOT: definition + lab hour + one failure.

NOT — sample query

-- NOT
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;

NOT: create two demo rows, then SELECT qty >= 2 ordered. Say which labels come back.

Short notes

DefNOT — Farhan uses it for a NOT dry-run in lab hour.
RuleNOT → one NOT step Farhan can write from memory.
RememberNOT + an index (lab hour).
UseNOT in lab hour (a NOT dry-run).
TrapNOT — copy-pasting NOT without a dry-run.
ExNOT → a NOT dry-run.

-- NOT 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;

NOT

NOT — sample query

Short notes

Questions

NOT

NOT — sample query

Short notes

Questions