select a.merchant_id, a.merchant_name, round(sum(sale_amount)/(count(distinct refund_id)*count(distinct satisfaction_id)),2) total_sales_amount, round(sum(refund_amount)/(count(distinct sale_id)*count(distinct satisfaction_id)),2) total_refund_amount, round(avg(satisfaction_score),2) average_satisfa...

select a.courier_id, courier_name, round( avg(base_salary) + sum(delivery_fee) / count(distinct c.expense_id) - sum(expense_amount) / count(distinct b.delivery_id), 2 ) total_income from couriers_info a left join deliveries_info b on a.courier_id = b.courier_id left join expenses_info c on a.courier...