Introduction
Multiple metrics for a single object
Metrics for two groups
Ratios and percentages
Global vs. specific metrics
Instruction
Very well done! One more thing we can do is show ratios/percentages in groups. Take a look:
SELECT
ship_country,
COUNT(CASE
WHEN shipped_date IS NOT NULL
THEN order_id
END) AS count_shipped,
COUNT(order_id) AS count_all,
ROUND(COUNT(CASE
WHEN shipped_date IS NOT NULL
THEN order_id
END) / COUNT(order_id)::decimal * 100, 2) AS shipped_ratio
FROM orders
GROUP BY ship_country;
We've added the ship_country column to the GROUP BY and SELECT clauses. This way, we'll see the percentage of shipped orders for each country separately.
Exercise
Modify the template query so that it shows all data grouped by product category. Add category_name as the first column in the SELECT clause.
Stuck? Here's a hint!
Join the products and categories tables. Group by category ID and category name.
