SQL · Theory

time_format()

Theory

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time_format()

time_format() is simple if you keep it on paper. Meera uses it for time_format on Meera's board in lab hour.

time_format() on the board: one time_format step Meera can write from memory. Then say what time_format on Meera's board looks like after.

time_format() exists so Meera can keep time_format on Meera's board correct in lab hour.

Meera ships time_format() in lab hour. That is the use case worth saying.

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

time_format() is not a lonely heading. Meera ties it to time_format on Meera's board.

One breath for time_format(), then time_format on Meera's board, then only reciting the name of time_format. Sit down.

Exam tip

Board: time_format on Meera's board. Dry-run time_format(). Name the trap: only reciting the name of time_format.

time_format() — sample query

-- time_format()
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;

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

Short notes

Deftime_format() — Meera uses it for time_format on Meera's board in lab hour.
Ruletime_format() → one time_format step Meera can write from memory.
Remembertime_format() + the query planner (lab hour).
Usetime_format() in lab hour (time_format on Meera's board).
Traptime_format() — only reciting the name of time_format.
Extime_format() → time_format on Meera's board.

-- time_format() 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;

time_format()

time_format() — sample query

Short notes

Questions

time_format()

time_format() — sample query

Short notes

Questions