SQL · Theory

min()

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Theory

121/439

min()

If you can teach min() using a min dry-run, you know it. If you only know the heading, you don’t.

For min(), the query planner is in play. Don’t blame it until you have traced a min dry-run.

min() exists so Ananya can keep a min dry-run correct in lab hour.

Use min() when a min dry-run must stay clear. If a simpler SQL step works, use that instead.

min() trap — skipping the failure case for min. Ananya loses marks for that every viva.

Place min() next to nearby SQL work — one min step Ananya can write from memory is the link.

Viva for min(): what it is → one min step Ananya can write from memory → the mistake (skipping the failure case for min).

Exam tip

For min(): definition + lab hour + one failure.

min() — sample query

CREATE TABLE scores (id INTEGER PRIMARY KEY, marks INTEGER);
INSERT INTO scores VALUES (1, 80), (2, 90), (3, 70);
SELECT COUNT(*) AS n, AVG(marks) AS avg_marks, MAX(marks) AS top
FROM scores;

min() — aggregate functions collapse many rows into one summary row.

Short notes

Defmin() — Ananya uses it for a min dry-run in lab hour.
Rulemin() → one min step Ananya can write from memory.
Remembermin() + the query planner (lab hour).
Usemin() in lab hour (a min dry-run).
Trapmin() — skipping the failure case for min.
Exmin() → a min dry-run.

SQL · Theory

min()

← All stacks

Theory

121/439

min()

If you can teach min() using a min dry-run, you know it. If you only know the heading, you don’t.

For min(), the query planner is in play. Don’t blame it until you have traced a min dry-run.

min() exists so Ananya can keep a min dry-run correct in lab hour.

Use min() when a min dry-run must stay clear. If a simpler SQL step works, use that instead.

min() trap — skipping the failure case for min. Ananya loses marks for that every viva.

Place min() next to nearby SQL work — one min step Ananya can write from memory is the link.

Viva for min(): what it is → one min step Ananya can write from memory → the mistake (skipping the failure case for min).

Exam tip

For min(): definition + lab hour + one failure.

min() — sample query

CREATE TABLE scores (id INTEGER PRIMARY KEY, marks INTEGER);
INSERT INTO scores VALUES (1, 80), (2, 90), (3, 70);
SELECT COUNT(*) AS n, AVG(marks) AS avg_marks, MAX(marks) AS top
FROM scores;

min() — aggregate functions collapse many rows into one summary row.

Short notes

Defmin() — Ananya uses it for a min dry-run in lab hour.
Rulemin() → one min step Ananya can write from memory.
Remembermin() + the query planner (lab hour).
Usemin() in lab hour (a min dry-run).
Trapmin() — skipping the failure case for min.
Exmin() → a min dry-run.

min()

min() — sample query

Short notes

Questions

min()

min() — sample query

Short notes

Questions