Aggregation: GROUP BY & HAVING

📄 MySQLLesson 7Intermediate

Aggregation collapses multiple matching rows into calculation fields using SUM, AVG, COUNT, MIN, and MAX operations.

1 Grouping Results

SQL — Aggregations

# Calculate count of posts per user
SELECT user_id, COUNT(id) AS total_posts
FROM posts
GROUP BY user_id;

# GROUP BY with HAVING filter constraint on aggregated results
SELECT user_id, COUNT(id) AS total_posts
FROM posts
GROUP BY user_id
HAVING total_posts > 5;

2 Code Challenge

Challenge: Write a query groups products by category, displaying category name, average product price, and total stock quantity. Filter out categories having average price below $10.