SELECT

query_name,

ROUND(AVG(CAST(rating AS DECIMAL) / position), 2) AS quality,

ROUND((SUM(CASE WHEN rating < 3 THEN 1 ELSE 0 END) / COUNT(*)) * 100, 2) AS poor_query_percentage

FROM

Queries

query_name IS NOT NULL

GROUP BY

query_name;

SELECT DATE_FORMAT(trans_date, '%Y-%m') AS month,

country,

COUNT(id) AS trans_count,

SUM(CASE WHEN state = 'approved' THEN 1 ELSE 0 END) AS approved_count,

SUM(amount) AS trans_total_amount,

SUM(CASE WHEN state = 'approved' THEN amount ELSE 0 END) AS approved_total_amount

FROM Transactions

GROUP BY month, country