SQL · Theory

Subtime()

Theory

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Subtime()

If you can teach Subtime() using Ananya walking through Subtime, you know it. If you only know the heading, you don’t.

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

Subtime() exists so Ananya can keep Ananya walking through Subtime correct in a campus project.

Ananya ships Subtime() in a campus project. That is the use case worth saying.

Subtime() trap — only reciting the name of Subtime. Ananya loses marks for that every viva.

Subtime() is not a lonely heading. Ananya ties it to Ananya walking through Subtime.

Close Subtime() with: “If I skip it, Ananya walking through Subtime goes wrong like this: only reciting the name of Subtime.”

Exam tip

Board: Ananya walking through Subtime. Dry-run Subtime(). Name the trap: only reciting the name of Subtime.

Subtime() — sample query

-- Subtime()
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;

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

Short notes

DefSubtime() — Ananya uses it for Ananya walking through Subtime in a campus project.
RuleSubtime() → one Subtime step Ananya can write from memory.
RememberSubtime() + an index (a campus project).
UseSubtime() in a campus project (Ananya walking through Subtime).
TrapSubtime() — only reciting the name of Subtime.
ExSubtime() → Ananya walking through Subtime.

-- Subtime() 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;

Subtime()

Subtime() — sample query

Short notes

Questions

Subtime()

Subtime() — sample query

Short notes

Questions