mysql查询通过根据日期添加总和从2张表中获取结果

Question

我有这样的查询，我能够分别获取两个表的数据。 这个概念是我要按月分组金额。 从任何一张表中，我都可以正确检索金额，但是我必须从两个表格中获得金额之和，具体取决于月份。

(select SUM(amount) as amount
     , month(reciept_date) as month
     , year(reciept_date) as year 
 from sg_chool 
 where academic_year = '2' 
 group by MONTH(reciept_date)) 

UNION ALL 

(select SUM(amount_paid) as amount
      , month(reciept_date) as month
      , year(reciept_date) as year 
 from sg_fees 
 where academic_year = '2' 
 group by MONTH(reciept_date))

Answer 1

尝试这个

SELECT sum(temp.amount) as amount, temp.month, temp.year
FROM (
(select SUM(amount) as amount
     , month(reciept_date) as month
     , year(reciept_date) as year 
 from sg_chool 
 where academic_year = '2' 
 group by MONTH(reciept_date)) 

UNION ALL 

  (select SUM(amount_paid) as amount
      , month(reciept_date) as month
      , year(reciept_date) as year 
 from sg_fees 
 where academic_year = '2' 
 group by MONTH(reciept_date))
 ) as temp
GROUP BY temp.month;

Answer 2

这可能满足您的需求：

SELECT
  (school.amount + fees.amount) AS amount
    , school.month
    , school.year
FROM
  (SELECT SUM(amount) AS amount
    , month(reciept_date) AS month
    , year(reciept_date) AS year 
   FROM sg_chool 
   WHERE academic_year = '2' 
   GROUP BY MONTH(reciept_date)) AS school
JOIN
  (SELECT SUM(amount_paid) AS amount
    , month(reciept_date) AS month
   FROM sg_fees 
   WHERE academic_year = '2'
   GROUP BY MONTH(reciept_date)) AS fees
USING (month)

您可以在这里尝试。