mysql - MySQL子查询问题

Question

我想要的结果，'

price1   |  price2 
1. 10000 |  2. -100 
3. 20000 |  4. -200

将选择的查询，

1. select total_price from cloud_payment where user_id='snoopy99' and demandnum= '201307-charge0000040C'

2. select unpaid_price from gcloud.cloud_service_basic where user_id='snoopy99' and month=7

3. select total_price from gcloud.cloud_payment where user_id='snoopy99' and demandnum= '201308-charge0000040C'

4. select unpaid_price from gcloud.cloud_service_basic where user_id='snoopy99' and month=8

我希望1,3在第一列 2,4在第二列。

有什么好主意吗？

Answer 1

尝试。

select total_price as price from cloud_payment where user_id='snoopy99' and (demandnum= '201307-charge0000040C' OR demandnum= '201308-charge0000040C')
UNION ALL
select unpaid_price as price from gcloud.cloud_service_basic where user_id='snoopy99' and ( month=7 OR month=8)

Answer 2

您可以使用JOIN从您的服务和付款表中选择一条合并记录，然后UNION选择两条这样的记录。像这样的东西：

SELECT total_price, unpaid_price
    FROM  cloud_payment cp
    JOIN  gcloud.cloud_service_basic cs ON cp.user_id = cs.user_id
    WHERE cp.user_id = 'snoopy99'
    AND   cp.demandnum = '201307-charge0000040C'
    AND   cs.month = 7
UNION
SELECT total_price, unpaid_price
    FROM  cloud_payment cp2
    JOIN  gcloud.cloud_service_basic cs2 ON cp2.user_id = cs2.user_id
    WHERE cp2.user_id = 'snoopy99'
    AND   cp2.demandnum = '201308-charge0000040C'
    AND   cs2.month = 8
;

示例 SQLFiddle。