我需要做什么我总结基于VARCHAR列值和年份范围的MySQL表的列值。也许这是令人困惑的，所以我会提出一个基本的例子：
列：id（对此没用），fruit_type，date_of_sale，sale_type，price
基本查询：
SELECT * FROM fruits
给了我：
1 APPLES 2018-05-30 GOOD 50.50
2 APPLES 2018-05-30 BAD -20.50
3 APPLES 2018-05-30 GOOD 40.00
4 APPLES 2018-05-30 BAD -10.50
5 APPLES 2017-05-29 GOOD 39.50
6 APPLES 2017-05-29 BAD -10.00
7 APPLES 2017-05-29 GOOD 30.00
8 APPLES 2017-05-29 BAD -20.00
9 BANANAS 2018-05-29 GOOD 20.00
10 BANANAS 2018-05-29 BAD 20.00
11 BANANAS 2018-05-29 GOOD 10.00
12 BANANAS 2018-05-29 BAD -5.00
13 BANANAS 2017-05-29 GOOD 50.00
14 BANANAS 2017-05-29 BAD -3.00
15 BANANAS 2017-05-29 GOOD 10.00
16 BANANAS 2017-05-29 BAD -3.00
17 ORANGES 2018-05-28 GOOD 5.00
18 ORANGES 2018-05-28 BAD -1.00
19 ORANGES 2017-05-28 GOOD 10.00
20 ORANGES 2017-05-28 BAD -1.00
我需要做些什么：
Fruit Sales 2017 Bad Sales 2017 Total 2017 Sales 2018 Bad Sales 2018 Total 2018
APPLES 69.50 -30.00 39.50 90.50 -30.50 60.00
BANANAS 60.00 -6.00 54.00 30.00 -10.00 20.00
ORANGES 10.00 -1.00 9.00 5.00 -1.00 5.00
我一直在尝试的查询是：
SELECT fruit_type AS Fruit,\
(SELECT SUM(price) FROM fruits WHERE sale_type='GOOD' AND date_of_sale BETWEEN '2017-01-01' AND '2017-12-31') AS Sales_2017,\
(SELECT SUM(price) FROM fruits WHERE sale_type='BAD' AND date_of_sale BETWEEN '2017-01-01' AND '2017-12-31') AS Bad_Sales_2017,\
(SELECT SUM(Sales_2017-Bad_Sales_2017)),\
(SELECT SUM(price) FROM fruits WHERE sale_type='GOOD' AND date_of_sale BETWEEN '2018-01-01' AND '2018-12-31') AS Sales_2018,\
(SELECT SUM(price) FROM fruits WHERE sale_type='BAD' AND date_of_sale BETWEEN '2018-01-01' AND '2018-12-31') AS Bad_Sales_2018,\
(SELECT SUM(Sales_2018-Bad_Sales_2018)),\
FROM fruits
GROUP BY fruit_type;
问题是查询返回的值是整个列的总和，其值为GOOD或BAD，而不是水果类型匹配的值GOOD。
需要一些针对该问题的提示。
答案 0 :(得分：4)
使用sum + case when condition汇总您的销售
试一试：
select
fruit_type AS Fruit,
sum(
case when date_of_sale between '2017-01-01 00:00:00' and '2017-12-31 00:00:00' then
case when sale_type = 'GOOD' then price else 0 end
else 0 end
) "Sales 2017",
sum(
case when date_of_sale between '2017-01-01 00:00:00' and '2017-12-31 00:00:00' then
case when sale_type = 'BAD' then price else 0 end
else 0 end
) "Bad Sales 2017",
sum(
case when date_of_sale between '2017-01-01 00:00:00' and '2017-12-31 00:00:00' then
price
else 0 end
) "Total 2017",
sum(
case when date_of_sale between '2018-01-01 00:00:00' and '2018-12-31 00:00:00' then
case when sale_type = 'GOOD' then price else 0 end
else 0 end
) "Sales 2018",
sum(
case when date_of_sale between '2018-01-01 00:00:00' and '2018-12-31 00:00:00' then
case when sale_type = 'BAD' then price else 0 end
else 0 end
) "Bad Sales 2018",
sum(
case when date_of_sale between '2018-01-01 00:00:00' and '2018-12-31 00:00:00' then
price
else 0 end
) "Total 2018"
FROM fruits
GROUP BY fruit_type;
答案 1 :(得分：1)
SELECT T.FRUIT,
SUM(IF(T.YEAR='2017' AND T.sale_type='GOOD',T.price_per_year,0)) `Sales 2017`,
SUM(IF(T.YEAR='2017' AND T.sale_type='BAD',T.price_per_year,0)) `Bad Sales 2017`,
SUM(IF(T.YEAR='2017',T.price_per_year,0)) `Total 2017`,
SUM(IF(T.YEAR='2018' AND T.sale_type='GOOD',T.price_per_year,0)) `Sales 2018`,
SUM(IF(T.YEAR='2018' AND T.sale_type='BAD',T.price_per_year,0)) `Bad Sales 2018`,
SUM(IF(T.YEAR='2018',T.price_per_year,0)) `Total 2018`
FROM (SELECT
FRUIT_TYPE FRUIT,
YEAR(date_of_sale) YEAR,
sale_type,
SUM(price) price_per_year
FROM fruits
GROUP BY
FRUIT_TYPE,
YEAR(date_of_sale),
sale_type) T
GROUP BY FRUIT
ORDER BY T.FRUIT;
查看有效的DEMO on SQL Fiddle。
答案 2 :(得分：-1)
试试这个，只需为你想要的每一行添加更多的子选择。
SELECT all2017.fruit_type as Fruit
,Sales_2017
,Bad_Sales_2017
from (SELECT fruit_type
,SUM(ABS(price)) Sales_2017
FROM fruits
WHERE year(date) = 2017
GROUP BY fruit_type) as all2017
join (SELECT fruit_type
,SUM(ABS(price)) Bad_Sales_2017
FROM fruits
WHERE year(date) = 2017
AND sales_type = 'BAD'
GROUP BY fruit_type) as bad2017
on all2017.fruit_type = bad2017.fruit_type