Mysql 使用 group by 和 having 子句查询

Question

我正在构建查询以获取同一产品的最高价格。我有 table 作为

-----------------------------------------
|   prod_id  |   price   |    user_id   |
-----------------------------------------
|     4      |   25      |       1      |
|     4      |   38      |       2      |
|     4      |   41      |       3      |
|     7      |   100     |       1      |
|     7      |   95      |       2      |
-----------------------------------------

我正在尝试获得以下输出：

-----------------------------------------
|     4      |   41      |       3      |
-----------------------------------------
|     7      |   100     |       1      |
-----------------------------------------

我构造了以下不正确的查询。

select * from user_bid group by prod_id having max(price);

谁能指导我获得所需结果的查询。

Answer 1

这是一个使用连接的选项：

SELECT p1.*
FROM prod_id
INNER JOIN
(
    SELECT prod_id, MAX(price) AS price    -- this inner subquery finds the maximum
    FROM user_bid                          -- price for each product group
    GROUP BY prod_id
) p2
    ON p1.prod_id = p2.prod_id AND         -- and this join condition retains
       p1.price   = p2.price               -- only records which have this maximum
                                           -- price for each product group

这是一个使用子查询的选项：

SELECT p1.*
FROM prod_id p1
WHERE price = (SELECT MAX(p2.price) FROM prod_id p2 WHERE p1.prod_id = p2.prod_id)

Answer 2

对于SQL服务器

;WITH cte AS

(
SELECT prod_id,price,user_id,
       ROW_NUMBER() OVER(PARTITION BY prod_id ORDER BY price desc) as rank
FROM table Name
)

SELECT prod_id,price,user_id
FROM cte
WHERE rank=1

Answer 3

SELECT *
FROM user_bid 
WHERE (prodid, price) IN
(
    SELECT prodid, MAX(price)
    FROM user_bid 
    GROUP BY prod_id
)

Answer 4

使用以下查询：

SELECT * FROM (SELECT * FROM user_bid  ORDER BY price DESC) AS Temp 
GROUP BY prod_id

输出：

Mysql 使用 group by 和 having 子句查询

Mysql query with group by and having clause

mysql

sql

group-by

having