力扣sql简单篇练习(三十)

# Write your MySQL query statement below
SELECT s.user_id,sum(s.quantity*p.price) spending
FROM Sales s
INNER JOIN Product p
ON s.product_id=p.product_id
GROUP BY s.user_id
ORDER BY spending desc,s.user_id asc

# Write your MySQL query statement below
SELECT t1.team_name home_team,t2.team_name away_team
FROM Teams t1
CROSS JOIN Teams t2
ON t1.team_name <> t2.team_name

# Write your MySQL query statement below
SELECT teacher_id,count(distinct subject_id) cnt
FROM Teacher
GROUP BY teacher_id