带有 CTE 和 Sum 的 SQL 联合

Question

我完全是 SQL 新手，并且有两个查询到我想要的结果，但我认为我没有正确使用 UNION 来组合它们。我之前在这个网站上得到了一些帮助，其中有一部分是查询。 以下是我所拥有的缩短版本。

WITH RemoveData
     AS (SELECT a.PLANT_NO,
                a.ALLOC_WHDV_VOL,
                a.KW_CTR_REDELIVERED_HV,
                a.MTR_NO,
                a.MTR_SFX,
                a.TRNX_ID,
                a.REC_STATUS_CD,
                MAX(a.ACCT_DT) ACCT_DT
         FROM   GasStmt a
                INNER JOIN SettleSum c
                  ON a .= c.TRNX_ID
                     AND a.MTR_NO
                         ||a.MTR_SFX = c.MTR_NO
                                       ||c.MTR_SFX
                LEFT OUTER JOIN FuelsCat d
                  ON a.TRNX_ID = d.TRNX_ID
                     AND a.MTR_NO
                         ||a.MTR_SFX = d.MTR_NO
                                       ||d.MTR_SFX
         WHERE  a.REC_STATUS_CD = 'RR'
         GROUP  BY a.PLANT_NO,
                   a.ALLOC_WHDV_VOL,
                   a.KW_CTR_REDELIVERED_HV,
                   a.MTR_NO,
                   a.MTR_SFX,
                   a.TRNX_ID,
                   a.REC_STATUS_CD
         HAVING COUNT(a.REC_STATUS_CD) > 2) 
SELECT plant_no                   "PlantNumber",
       SUM(-a.ALLOC_WHDV_VOL)     "PlantStandardGrossWellheadMcf",
       SUM(KW_CTR_REDELIVERED_HV) "KeepWholeResidueMMBtu"
FROM   RemoveData a
GROUP  BY plant_no
UNION
SELECT a.PLANT_NO            "PlantNumber",
       SUM(a.ALLOC_WHDV_VOL) "PlantStandardGrossWellheadMcf",
       SUM(CASE
             WHEN a.REC_STATUS_CD = 'RR' THEN -a.KW_CTR_REDELIVERED_HV
             ELSE a.KW_CTR_REDELIVERED_HV
           END)              "KeepWholeResidueMMBtu"
FROM   GasStmt a
       INNER JOIN SettleSum c
         ON a.TRNX_ID = c.TRNX_ID
            AND a.MTR_NO
                ||a.MTR_SFX = c.MTR_NO
                              ||c.MTR_SFX
       LEFT OUTER JOIN FuelsCat d
         ON a.TRNX_ID = d.TRNX_ID
            AND a.MTR_NO
                ||a.MTR_SFX = d.MTR_NO
                              ||d.MTR_SFX
       LEFT OUTER JOIN (SELECT MTR_NO,
                               MTR_SFX,
                               TRNX_ID,
                               REC_STATUS_CD,
                               MAX(ACCT_DT) ACCT_DT
                        FROM   GasStmt
                        WHERE  REC_STATUS_CD = 'RR'
                        GROUP  BY MTR_NO,
                                  MTR_SFX,
                                  TRNX_ID,
                                  REC_STATUS_CD
                        HAVING COUNT(TRNX_ID) > 1) b
         ON a.MTR_NO = b.MTR_NO
            AND a.TRNX_ID = b.TRNX_ID
            AND a.Rec_Status_Cd = b.REC_STATUS_CD
            AND a.Acct_Dt = b.ACCT_DT
WHERE  TO_CHAR(a.PROD_DT, 'YYYY') >= TO_CHAR(ADD_MONTHS(SYSDATE, -36), 'YYYY')
       AND a.STATUS_UNIT_TM_CD = 'M'
       AND b.MTR_NO IS NULL
GROUP  BY a.PLANT_NO 

以上查询返回：

PlantNumber | PlantStandardGrossWellheadMcf    |KeepWholeResidueMMBtu
2           | 0                                | -3.96
2           | 80                               |  100
43          | 150                              |  0
133         | 75                               |  0

如果我单独使用 CTE 运行第一个查询，我会得到以下结果：

PlantNumber | PlantStandardGrossWellheadMcf  |KeepWholeResidueMMBtu
2           | 0                              |-3.96

自行运行第二个查询，这是我得到的示例数据示例：

PlantNumber | PlantStandardGrossWellheadMcf    |KeepWholeResidueMMBtu
2           | 80                               |  100
43          | 150                              |  0
133         | 75                               |  0

我的预期结果是根据植物编号组合数据。可以用 UNION 完成还是我做错了什么？这是我希望实现的目标：

PlantNumber | PlantStandardGrossWellheadMcf    |KeepWholeResidueMMBtu
2           | 80                               |  96.04
43          | 150                              |  0
133         | 75                               |  0

Answer 1

您可以将 UNION 语句的结果作为子查询执行聚合函数。根据您的特定 DBMS 可能会有一些变化，但是这个示例元代码应该解释这个概念：

SELECT "Results".ColA, "Results".SUM(ColB), "Results".SUM(ColC)
FROM (
      SELECT ColA, ColB, ColC
      FROM SomeTable1
      INNER JOIN SomeOtherTable1
      WHERE Criteria

      UNION

      SELECT ColA, ColB, ColC
      FROM SomeTable2
      INNER JOIN SomeOtherTable2
      WHERE Criteria
     ) "Results"

GROUP BY "Results".ColA