Question

我有2个具有相同结构的表，每个表使用几乎相同的sql来选择和SUM。

SQL1：

SELECT YEAR, SUM(GENERATION) AS generationB, SUM(TRANSMISSION) AS transmissionB
FROM tableB 
WHERE YEAR BETWEEN '2013' AND  '2016' 
AND POWER_PLANT_ID = 'ABC1' 
AND STATUS = 'V' 
AND transmission IS NOT NULL 
GROUP BY YEAR

SQL2：

AssertionError

如何将这个2 sql组合到其年份？

Answer 1

试试这个

select year, sum(generationA) as generationA, sum(transmissionA) as transmissionA from
(
SELECT YEAR, SUM(GENERATION) AS generationA, SUM(TRANSMISSION) AS transmissionA
FROM tableA 
WHERE YEAR BETWEEN '2013' AND  '2016' 
AND POWER_PLANT_ID = 'ABC1' 
AND STATUS = 'V' 
AND transmission IS NOT NULL 
GROUP BY YEAR
union all
SELECT YEAR, SUM(GENERATION) AS generationB, SUM(TRANSMISSION) AS transmissionB
FROM tableB 
WHERE YEAR BETWEEN '2013' AND  '2016' 
AND POWER_PLANT_ID = 'ABC1' 
AND STATUS = 'V' 
AND transmission IS NOT NULL 
GROUP BY YEAR
) as t
group by YEAR

Answer 2

您可以使用联接

  SELECT 
          a.YEAR
        , SUM(a.GENERATION) AS generationA
        , SUM(a.TRANSMISSION) AS transmissionA
        , SUM(b.GENERATION) AS generationB
        , SUM(b.TRANSMISSION) AS transmissionB
  FROM tableA  as a 
  LEFT JOIN tableB as b on  (a.YEAR = b.year 
                              and a..POWER_PLANT_ID = b.POWER_PLANT_ID 
                              and a.STATUS = b.STATUS
                               and a.transmission = b.transmission)
  WHERE a.YEAR BETWEEN '2013' AND  '2016' 
  AND a.POWER_PLANT_ID = 'ABC1' 
  AND a.STATUS = 'V' 
  AND a.transmission IS NOT NULL 
  GROUP BY a.YEAR

Answer 3

如果您想通过分组年份来总结结果集，请尝试使用以下脚本。

SELECT YEAR,SUM(GENERATION) generation,SUM(TRANSMISSION)TRANSMISSION
FROM
(SELECT YEAR, GENERATION , TRANSMISSION 
FROM tableA 
WHERE YEAR BETWEEN '2013' AND  '2016' 
AND POWER_PLANT_ID = 'ABC1' 
AND STATUS = 'V' 
AND transmission IS NOT NULL 


UNION ALL 

SELECT YEAR, GENERATION, TRANSMISSION
FROM tableB 
WHERE YEAR BETWEEN '2013' AND  '2016' 
AND POWER_PLANT_ID = 'ABC1' 
AND STATUS = 'V' 
AND transmission IS NOT NULL )AS t
GROUP BY YEAR

MYSQL：按年计算2个计数sql组

3 个答案: