SQL Window Functions and CTEs

SQL window functions let you compute rankings and aggregates without collapsing rows.

Using OVER(), PARTITION BY, and ORDER BY, they analyze data such as exam scores by group.

ROW_NUMBER, RANK, DENSE_RANK, LAG, and NTILE handle ranking, prior-value checks, and bucketing.

These features solve analytical queries that are awkward or impossible with only SELECT, WHERE, JOIN, and GROUP BY.

The article then begins to transition into CTEs, introducing the topic but not yet detailing it.