在 Oracle 中加入多个 CTE 时遇到重复问题

Question

我正在创建三个 CTE，我最终希望将它们连接在一起以创建一个汇总表。三个表中的两个包含相同的列，只是它们相加的项目不同（报价与新业务）。另一个表包含两个汇总列，报告排序和总成本，以及另一个字段的子类别，报告类型，它汇总到 LOB。

当我尝试将它们全部连接在一起并“重新汇总”这些字段时，就会出现问题。出于某种原因，即使我在 select 子句中使用了 DISTINCT 并且我认为我正确地加入了所有内容，我也会得到重复的值。

当我从 Total_Quotes 和 Total_NB 中删除 SUM 时，代码有效；但是，我希望将一条只有一个值的行相加就可以了。显然不是这样的。

WITH
MONTHLY_INVOICES AS
(SELECT DISTINCT
EXTRACT(YEAR FROM INVOICE_DATE) AS YEAR
,EXTRACT(MONTH FROM INVOICE_DATE) AS MONTH
,STATE
,REPORT_TYPE
,CASE WHEN REPORT_TYPE IN ('ADD', 'CCA', 'CLA', 'MVR', 'VIN') THEN 'AUTO'
      WHEN REPORT_TYPE IN ('CCP', 'CLP') THEN 'HOME'
      WHEN REPORT_TYPE IN ('DPF', 'NCF') THEN 'OTHER'
      END AS LOB
,SUM(TOTAL_ORDERS) AS TOTAL_ORDERS
,SUM(TOTAL_COST) AS TOTAL_COST
FROM
KAHJZK_VENDOR_INVOICE_TOTALS
GROUP BY
EXTRACT(YEAR FROM INVOICE_DATE)
,EXTRACT(MONTH FROM INVOICE_DATE)
,STATE
,REPORT_TYPE
,CASE WHEN REPORT_TYPE IN ('ADD', 'CCA', 'CLA', 'MVR', 'VIN') THEN 'AUTO'
      WHEN REPORT_TYPE IN ('CCP', 'CLP') THEN 'HOME'
      WHEN REPORT_TYPE IN ('DPF', 'NCF') THEN 'OTHER'
      END)

,MONTHLY_QT AS 
(SELECT DISTINCT
EXTRACT(YEAR FROM REPORT_DATE) AS YEAR
,EXTRACT(MONTH FROM REPORT_DATE) AS MONTH
,STATE
,LOB
,SUM(TOTAL_QUOTES) AS TOTAL_QTS
FROM KAHJZK_DAILY_QT_VOL
WHERE
EXTRACT(YEAR FROM REPORT_DATE) >= '2019'
GROUP BY
EXTRACT(YEAR FROM REPORT_DATE)
,EXTRACT(MONTH FROM REPORT_DATE)
,STATE
,LOB)

,MONTHLY_NB AS 
(SELECT DISTINCT
EXTRACT(YEAR FROM REPORT_DATE) AS YEAR
,EXTRACT(MONTH FROM REPORT_DATE) AS MONTH
,STATE
,LOB
,SUM(TOTAL_POLICIES) AS TOTAL_NB
FROM KAHJZK_DAILY_NB_VOL
WHERE
EXTRACT(YEAR FROM REPORT_DATE) >= '2019'
GROUP BY
EXTRACT(YEAR FROM REPORT_DATE)
,EXTRACT(MONTH FROM REPORT_DATE)
,STATE
,LOB)


SELECT DISTINCT
A.YEAR
,A.MONTH
,A.STATE
,A.LOB
,SUM(A.TOTAL_ORDERS)
,SUM(A.TOTAL_COST)
,SUM(B.TOTAL_QTS)
,SUM(C.TOTAL_NB)
FROM
MONTHLY_INVOICES A
LEFT OUTER JOIN MONTHLY_QT B
ON A.YEAR = B.YEAR
AND A.MONTH = B.MONTH
AND A.STATE = B.STATE
AND A.LOB = B.LOB
LEFT OUTER JOIN MONTHLY_NB C
ON A.YEAR = C.YEAR
AND A.MONTH = C.MONTH
AND A.STATE = C.STATE
AND A.LOB = C.LOB
GROUP BY
A.YEAR
,A.MONTH
,A.STATE
,A.LOB
ORDER BY
3,4,1,2;

当我将最后一部分更改为以下内容时，代码有效。：

SELECT DISTINCT
A.YEAR
,A.MONTH
,A.STATE
,A.LOB
,SUM(A.TOTAL_ORDERS)
,SUM(A.TOTAL_COST)
,B.TOTAL_QTS
,C.TOTAL_NB
FROM
MONTHLY_INVOICES A
LEFT OUTER JOIN MONTHLY_QT B
ON A.YEAR = B.YEAR
AND A.MONTH = B.MONTH
AND A.STATE = B.STATE
AND A.LOB = B.LOB
LEFT OUTER JOIN MONTHLY_NB C
ON A.YEAR = C.YEAR
AND A.MONTH = C.MONTH
AND A.STATE = C.STATE
AND A.LOB = C.LOB
GROUP BY
A.YEAR
,A.MONTH
,A.STATE
,A.LOB
,B.TOTAL_QTS
,C.TOTAL_NB
ORDER BY
3,4,1,2;

Answer 1

您不应该将 DISTINCT 与 GROUP BY 一起使用。 GROUP BY 将返回 GROUP BY 中字段的不同组合，并进行适当的求和。所以我认为你想做这样的事情：

WITH MONTHLY_INVOICES AS (SELECT EXTRACT(YEAR FROM INVOICE_DATE) AS YEAR
                                ,EXTRACT(MONTH FROM INVOICE_DATE) AS MONTH
                                ,STATE
                                ,REPORT_TYPE
                                ,CASE WHEN REPORT_TYPE IN ('ADD', 'CCA', 'CLA', 'MVR', 'VIN') THEN 'AUTO'
                                      WHEN REPORT_TYPE IN ('CCP', 'CLP') THEN 'HOME'
                                      WHEN REPORT_TYPE IN ('DPF', 'NCF') THEN 'OTHER'
                                      END AS LOB
                                ,SUM(TOTAL_ORDERS) AS TOTAL_ORDERS
                                ,SUM(TOTAL_COST) AS TOTAL_COST
                            FROM KAHJZK_VENDOR_INVOICE_TOTALS
                            GROUP BY EXTRACT(YEAR FROM INVOICE_DATE)
                                    ,EXTRACT(MONTH FROM INVOICE_DATE)
                                    ,STATE
                                    ,REPORT_TYPE
                                    ,CASE WHEN REPORT_TYPE IN ('ADD', 'CCA', 'CLA', 'MVR', 'VIN') THEN 'AUTO'
                                          WHEN REPORT_TYPE IN ('CCP', 'CLP') THEN 'HOME'
                                          WHEN REPORT_TYPE IN ('DPF', 'NCF') THEN 'OTHER'
                                          END),
     MONTHLY_QT AS (SELECT EXTRACT(YEAR FROM REPORT_DATE) AS YEAR
                          ,EXTRACT(MONTH FROM REPORT_DATE) AS MONTH
                          ,STATE
                          ,LOB
                          ,SUM(TOTAL_QUOTES) AS TOTAL_QTS
                      FROM KAHJZK_DAILY_QT_VOL
                      WHERE EXTRACT(YEAR FROM REPORT_DATE) >= 2019
                      GROUP BY EXTRACT(YEAR FROM REPORT_DATE)
                              ,EXTRACT(MONTH FROM REPORT_DATE)
                              ,STATE
                              ,LOB),
     MONTHLY_NB AS (SELECT EXTRACT(YEAR FROM REPORT_DATE) AS YEAR
                          ,EXTRACT(MONTH FROM REPORT_DATE) AS MONTH
                          ,STATE
                          ,LOB
                          ,SUM(TOTAL_POLICIES) AS TOTAL_NB
                     FROM KAHJZK_DAILY_NB_VOL
                     WHERE EXTRACT(YEAR FROM REPORT_DATE) >= 2019
                     GROUP BY EXTRACT(YEAR FROM REPORT_DATE)
                             ,EXTRACT(MONTH FROM REPORT_DATE)
                             ,STATE
                             ,LOB)
SELECT A.YEAR
      ,A.MONTH
      ,A.STATE
      ,A.LOB
      ,SUM(A.TOTAL_ORDERS)
      ,SUM(A.TOTAL_COST)
      ,SUM(B.TOTAL_QTS)
      ,SUM(C.TOTAL_NB)
  FROM MONTHLY_INVOICES A
  LEFT OUTER JOIN MONTHLY_QT B
    ON A.YEAR = B.YEAR
   AND A.MONTH = B.MONTH
   AND A.STATE = B.STATE
   AND A.LOB = B.LOB
  LEFT OUTER JOIN MONTHLY_NB C
   ON A.YEAR = C.YEAR
  AND A.MONTH = C.MONTH
  AND A.STATE = C.STATE
  AND A.LOB = C.LOB
  GROUP BY A.YEAR
          ,A.MONTH
          ,A.STATE
          ,A.LOB
  ORDER BY 3,4,1,2;

与您应该使用数字的EXTRACT 的结果（例如2019）进行比较时，您还使用了字符串（例如'2019'） - 我已经更新了。

试一试，看看它是否符合您的要求。

Answer 2

1. 您必须提供一个或多个列来唯一标识每个表中的每一行。
2. 您必须提供一种方法，可以将一个表中唯一标识的行连接到另一个表中唯一标识的行。

未能解决上面列出的两个项目将导致结果集是选择标准的笛卡尔积（也称为叉积）。

编辑（回复评论 1）
distinct 不会影响连接产生的叉积。 如果你得到一个交叉产品， 那么您可能在连接的一侧选择行 与另一侧的任何行都不匹配。

例如， 试试select a.field, b.field from table 1 a, table 2 b （即不加入，只列出两个表） 你会得到一个叉积。

如果您在添加 left join 子句。