力扣sql入门篇(九)

1 股票的资本损益

1.1 题目内容

1.1.1 基本题目信息

1.1.2 示例输入输出

1.2 示例sql语句

# 每个用户的所有Sell的price值减去Buy的price值就可以了
SELECT e.stock_name,sum(e.price) capital_gain_loss
FROM 
(
SELECT stock_name,operation,operation_day,price*-1 price
FROM Stocks
WHERE operation="Buy"
UNION ALL
SELECT stock_name,operation,operation_day, price
FROM Stocks
WHERE operation="Sell"
) e
GROUP BY stock_name

1.3 运行截图

2 排名靠前的旅行者

2.1 题目内容

2.1.1 基本题目信息

2.1.2 示例输入输出

2.2 示例sql语句

SELECT u.name,IFNULL(sum(r.distance),0) travelled_distance
FROM Users u
LEFT JOIN Rides r
ON u.id=r.user_id
GROUP BY u.id,u.name
ORDER BY travelled_distance desc,name asc;

2.3 运行截图

3 市场分析I

3.1 题目内容

3.1.1 基本题目信息1

3.1.2 基本题目信息2

3.1.3 示例输入输出

3.2 示例sql语句

SELECT u.user_id buyer_id,u.join_date join_date,IFNULL(o1.num,0)  orders_in_2019 
FROM Users u
LEFT JOIN
(
    SELECT buyer_id,count(*) num
    FROM Orders
    WHERE date_format(order_date,"%Y")=2019
    GROUP BY buyer_id 
) o1
ON u.user_id=o1.buyer_id
GROUP BY u.user_id

3.3 运行截图