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IS NOT NULL

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IS NOT NULL

IS NOT NULL is a SQL idea you prove with Farhan walking through IS NOT NULL, not with a slogan.

Keep IS NOT NULL small. Farhan should finish Farhan walking through IS NOT NULL in a few lines, not a 40-line dump.

IS NOT NULL exists so Farhan can keep Farhan walking through IS NOT NULL correct in a viva board.

Use IS NOT NULL when Farhan walking through IS NOT NULL must stay clear. If a simpler SQL step works, use that instead.

IS NOT NULL miss — only reciting the name of IS NOT NULL. Fix it before you talk about advanced SQL.

After IS NOT NULL, Farhan should still remember only reciting the name of IS NOT NULL.

Viva for IS NOT NULL: what it is → one IS NOT NULL step Farhan can write from memory → the mistake (only reciting the name of IS NOT NULL).

Exam tip

For IS NOT NULL: definition + a viva board + one failure.

IS NOT NULL — sample query

-- IS NOT NULL
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;

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

Short notes

DefIS NOT NULL — Farhan uses it for Farhan walking through IS NOT NULL in a viva board.
RuleIS NOT NULL → one IS NOT NULL step Farhan can write from memory.
RememberIS NOT NULL + the query planner (a viva board).
UseIS NOT NULL in a viva board (Farhan walking through IS NOT NULL).
TrapIS NOT NULL — only reciting the name of IS NOT NULL.
ExIS NOT NULL → Farhan walking through IS NOT NULL.

-- IS NOT NULL 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;

IS NOT NULL

IS NOT NULL — sample query

Short notes

Questions

IS NOT NULL

IS NOT NULL — sample query

Short notes

Questions