7. Grouping and Filtering

📄️ 7. Grouping and Filtering

Group data with GROUP BY and filter grouped results with HAVING.

📄️ GROUP BY

Choose and apply PostgreSQL GROUP BY patterns to summarize rows into reliable metrics while protecting data quality, storage efficiency, and query performance. Focus: GROUP BY.

📄️ HAVING Clause

Choose and apply PostgreSQL HAVING to filter grouped results while protecting data quality, storage efficiency, and query performance. Focus: HAVING Clause.

📄️ GROUP BY with ROLLUP / GROUPING SETS

Choose and apply PostgreSQL ROLLUP and GROUPING SETS to produce subtotals and grand totals while protecting data quality, storage efficiency, and query performance. Focus: GROUP BY with ROLLUP / GROUPING SETS.