Question

我正在尝试生成一个SQL语句，以对每个用户ID的类别中的前5个值求和，以创建总体总数。这可能吗，我该如何实现？我可以将每个类别或前5个类别的前5名加起来，但很难查看如何将各个类别的总和相加。

例如，

ID           Cater   Weight
--------------------------------
1            Cheese    10
2            Bacon     15
1            Cheese    5
2            Bacon     10
1            Cheese    22
2            Cheese    5
1            Bacon     10
1            Cheese    10
2            Cheese    5
1            Cheese    20
2            Bacon     10
1            Cheese    30

我正在寻找的结果是

ID      Total_Weight
-------------------
1            102    Top 5 Cheese (10+22+10+20+30) + Top 5 Bacon (10)
2            45     Top 5 Cheese (5+5) + Top 5 Bacon (15+10+10)

前5名之外的任何值都将被忽略。

下面的代码显示所有类别的AS总重量中前5名重量的总和。我可以通过一个语句实现我想要的吗？

$log = "SELECT id, cater,
    SUM(weight) AS total_weight
   FROM   (   SELECT id,
                 CASE WHEN @ID = ID THEN @ROW_NUMBER := @ROW_NUMBER + 1
                      ELSE @ROW_NUMBER := 1
                  END AS rn,
                 cater,
                 weight,
                 @id := id
            FROM individual,
                 (SELECT @ROW_NUMBER := 1, @ID := '') r
           ORDER
              BY
                 id, weight DESC
      ) TMP
 WHERE rn <= 5
   AND cater <> ''

   GROUP
BY id
 ORDER
BY total_weight DESC";

Answer 1

可能还有其他更好的解决方案。但这会提供您期望的结果-

SELECT B.id, 
SUM(T_weight) Total_Weight,
group_concat(concat('TOP 5 ',B.cater,' (',B.T,')') SEPARATOR ' ') Details
FROM
(
    SELECT ID,cater,SUM(Weight) T_weight,group_concat(weight SEPARATOR '+') T
    FROM 
    (    
        SELECT *    FROM
        (
            SELECT id,cater, CASE WHEN @ID = ID THEN @ROW_NUMBER := @ROW_NUMBER + 1 ELSE @ROW_NUMBER := 1 END AS rn,weight,@id := id
            FROM your_table,(SELECT @ROW_NUMBER := 1, @ID := ''
        ) r
        WHERE cater = 'Cheese' ORDER BY id, weight DESC
        )A WHERE rn < 6


        UNION ALL

        SELECT *    FROM
        (
            SELECT id,cater, CASE WHEN @ID = ID THEN @ROW_NUMBER := @ROW_NUMBER + 1 ELSE @ROW_NUMBER := 1 END AS rn,weight,@id := id
            FROM your_table,(SELECT @ROW_NUMBER := 1, @ID := ''
        ) r
        WHERE cater = 'Bacon' ORDER BY id, weight DESC
        )A WHERE rn < 6


        UNION ALL

        SELECT *    FROM
        (
            SELECT id,cater, CASE WHEN @ID = ID THEN @ROW_NUMBER := @ROW_NUMBER + 1 ELSE @ROW_NUMBER := 1 END AS rn,weight,@id := id
            FROM your_table,(SELECT @ROW_NUMBER := 1, @ID := ''
        ) r
        WHERE cater = 'Cat3' ORDER BY id, weight DESC
        )A WHERE rn < 6


        UNION ALL

        SELECT *    FROM
        (
            SELECT id,cater, CASE WHEN @ID = ID THEN @ROW_NUMBER := @ROW_NUMBER + 1 ELSE @ROW_NUMBER := 1 END AS rn,weight,@id := id
            FROM your_table,(SELECT @ROW_NUMBER := 1, @ID := ''
        ) r
        WHERE cater = 'Cat4' ORDER BY id, weight DESC
        )A WHERE rn < 6


        UNION ALL

        SELECT *    FROM
        (
            SELECT id,cater, CASE WHEN @ID = ID THEN @ROW_NUMBER := @ROW_NUMBER + 1 ELSE @ROW_NUMBER := 1 END AS rn,weight,@id := id
            FROM your_table,(SELECT @ROW_NUMBER := 1, @ID := ''
        ) r
        WHERE cater = 'Cat5' ORDER BY id, weight DESC
        )A WHERE rn < 6


        UNION ALL

        SELECT *    FROM
        (
            SELECT id,cater, CASE WHEN @ID = ID THEN @ROW_NUMBER := @ROW_NUMBER + 1 ELSE @ROW_NUMBER := 1 END AS rn,weight,@id := id
            FROM your_table,(SELECT @ROW_NUMBER := 1, @ID := ''
        ) r
        WHERE cater = 'Cat6' ORDER BY id, weight DESC
        )A WHERE rn < 6
    )A
    GROUP BY ID,Cater
)B
group by id

输出为-

1   191 TOP 5 Cheese (10+22+20+10+30) TOP 5 Cat3 (25+9+20+16+13) TOP 5 Bacon (10)
2   45  TOP 5 Cheese (5+5) TOP 5 Bacon (15+10+10)

Answer 2

如果您具有MySql版本8或更高版本，则可以使用以下代码：

vec_string

您需要MySql 8+，因为我使用了row_number函数，并且仅从版本8开始存在。在下面的小提琴示例中，我使用了Microsoft Sql Server 2017，因为它们没有MySql 8或更高版本。

您可以看到自己的示例here。

SQL SUM TOP 5每个类别的值，然后每个ID的SUM类别总计

2 个答案: