SQL · Theory

ORDER BY

Theory

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ORDER BY

Ananya only reaches for ORDER BY when ORDER BY on Ananya's board has to stay correct in a campus project.

ORDER BY on the board: one ORDER BY step Ananya can write from memory. Then say what ORDER BY on Ananya's board looks like after.

Skip ORDER BY and only reciting the name of ORDER BY shows up in a campus project.

Ananya ships ORDER BY in a campus project. That is the use case worth saying.

ORDER BY trap — only reciting the name of ORDER BY. Ananya loses marks for that every viva.

Place ORDER BY next to nearby SQL work — one ORDER BY step Ananya can write from memory is the link.

Close ORDER BY with: “If I skip it, ORDER BY on Ananya's board goes wrong like this: only reciting the name of ORDER BY.”

Exam tip

Board: ORDER BY on Ananya's board. Dry-run ORDER BY. Name the trap: only reciting the name of ORDER BY.

ORDER BY — sample query

CREATE TABLE sales (id INTEGER PRIMARY KEY, region TEXT, amount INTEGER);
INSERT INTO sales VALUES (1, 'N', 100), (2, 'N', 80), (3, 'S', 120);
SELECT region, SUM(amount) AS total
FROM sales
GROUP BY region
HAVING total >= 150
ORDER BY total DESC;

ORDER BY — gROUP BY aggregates; HAVING filters groups; ORDER BY sorts the result.

Short notes

DefORDER BY — Ananya uses it for ORDER BY on Ananya's board in a campus project.
RuleORDER BY → one ORDER BY step Ananya can write from memory.
RememberORDER BY + an index (a campus project).
UseORDER BY in a campus project (ORDER BY on Ananya's board).
TrapORDER BY — only reciting the name of ORDER BY.
ExORDER BY → ORDER BY on Ananya's board.

CREATE TABLE sales (id INTEGER PRIMARY KEY, region TEXT, amount INTEGER); INSERT INTO sales VALUES (1, 'N', 100), (2, 'N', 80), (3, 'S', 120); SELECT region, SUM(amount) AS total FROM sales GROUP BY region HAVING total >= 150 ORDER BY total DESC;

ORDER BY

ORDER BY — sample query

Short notes

Questions

ORDER BY

ORDER BY — sample query

Short notes

Questions