MySQL: Output ID based on SUM data in a column based attributes in 另一列

Question

SQL Table:

Customer	Type	Payment
1	Apples	5
1	Apples	5
1	Oranges	1
1	Oranges	2
2	Apples	7
2	Oranges	3
2	Oranges	6

根据以上内容，确定哪些客户为苹果支付的费用比橙子多，作为他们所有付款的总和。

如上table,

客户 1 - 苹果 10 > 橙子 3

客户 2 - 苹果 7 < 橘子 9

因此 SQL 应该输出 Customer 1

我尝试了多个查询，以下是最有希望的查询，但对组函数的使用无效错误代码 1111。

SELECT a.customer 
FROM (SELECT customer, SUM(payment) AS orangespaid FROM table
    WHERE type ='Oranges'
    GROUP BY customer) o
JOIN table AS a ON a.customer = o.customer
WHERE type = 'Apples' and SUM(payment) > orangespaid
GROUP BY customer
ORDER BY customer;

Answer 1

尝试将 SUM 移动到第二个子查询中

SELECT a.customer 
FROM (SELECT customer, SUM(payment) AS orangespaid FROM table
    WHERE type ='Oranges'
    GROUP BY customer) o
JOIN (SELECT customer, SUM(payment) AS applespaid FROM table
    WHERE type ='Apples'
    GROUP BY customer) AS a ON a.customer = o.customer
WHERE applespaid > orangespaid
ORDER BY customer;

Answer 2

您应该针对您想要的每种类型尝试使用 sum(case when)，它可能不是最佳解决方案，但它确实有效。

select a.customer
from (select as1.Customer, 
sum(case when type = 'Oranges' then payment else 0 end) AS orangespaid, 
sum(case when type = 'Apples' then payment else 0 end) AS applespaid
from as1 group by as1.Customer) a
where applespaid > orangespaid

dbfiddle here

Answer 3

有很多方法可以实现。

下面是没有子查询的方法：

SELECT Customer,
       SUM(CASE WHEN Type='Apples' THEN Payment ELSE 0 END) AS Apples,
       SUM(CASE WHEN Type='Oranges' THEN Payment ELSE 0 END) AS Oranges
  FROM table1
  GROUP BY Customer
HAVING Apples > Oranges;

或者像这样：

SELECT Customer,
      SUM(IF(Type='Apples',Payment,0)) > SUM(IF(Type='Oranges',Payment,0)) Chk
  FROM table1
  GROUP BY Customer
HAVING Chk=1

或者稍微修改上面的查询，而不是检查 SELECT 中的值然后从 HAVING 中过滤，为什么不直接在 HAVING 中进行检查：

SELECT Customer
  FROM table1
  GROUP BY Customer
HAVING SUM(IF(Type='Apples',Payment,0)) > SUM(IF(Type='Oranges',Payment,0)) != 0;

第一个查询也可以用类似的方式完成。

Demo fiddle

旁注：
至于使用CASE和IF的区别，基本上是一样的，看个人喜好吧。我主要选择使用 CASE 因为可读性和更易于编辑（parentheses/brackets 的使用不多）但是几乎每次使用 IF 都更短。

MySQL: Output ID based on SUM data in a column based attributes in 另一列

MySQL: Output ID based on SUM data in one column based attributes in another column

mysql

sum