Intermediate Database & SQL #SQL #query-narration #joins #window-functions

SQL Query Description Language

5 exercises — practise describing SQL operations in professional English: JOIN narration, window functions, aggregate queries, correlated subqueries, and JOIN type vocabulary.

SQL narration quick reference

SELECT clause: "projects columns" or "returns the [col] column"
JOIN: "performs an INNER/LEFT JOIN between [A] and [B] on the [FK] foreign key"
WHERE: "filters the result set WHERE [predicate]"
GROUP BY: "groups by [col] and returns [aggregate] per group"
Window function: "computed within a partition of [col], ordered by [col]"
Correlated subquery: "re-executes once per outer row, using [outer.col]"

Question 1 of