多列的内连接并在 INSERT INTO....SELECT 中使用

Question

表CUST_DAY0_MERGE有以下列

NEW_CUST_ID
ACTIVE_REF_ID
OLD_REF_ID_1
OLD_REF_ID_2
OLD_REF_ID_3

我想在表CUST_REVIEWS 中创建一个插入语句，包含以下列：

CUST_REVIEW_ID
RUN_DATE
CUST_ID
CUST_SOURCE_UNIQUE_ID
CUST_SOURCE_REF_ID

此插入语句需要与CUST_DAY0_MERGE 进行内连接查询，条件如下：

CUST_DAY0_MERGE.OLD_REF_ID_1`=`CUST_REVIEWS.CUST_SOURCE_REF_ID
CUST_DAY0_MERGE.OLD_REF_ID_2`=`CUST_REVIEWS.CUST_SOURCE_REF_ID
CUST_DAY0_MERGE.OLD_REF_ID_3`=`CUST_REVIEWS.CUST_SOURCE_REF_ID

如果满足上述条件，将向CUST_REVIEWS 插入一条新记录，条件如下：

CUST_REVIEWS.CUST_ID`=`CUST_DAY0_MERGE.NEW_CUST_ID
CUST_REVIEWS.CUST_SOURCE_UNIQUE_ID`=`CUST_DAY0_MERGE.NEW_CUST_ID

对于其他列应根据现有值保持不变。

我有一个如下示例语句：

INSERT INTO CUST_REVIEWS(CUST_REVIEW_ID,RUN_DATE,CUST_ID,CUST_SOURCE_UNIQUE_ID,CUST_SOURCE_REF_ID)
SELECT CUST_REVIEW_ID,RUN_DATE,CUST_ID,CUST_SOURCE_UNIQUE_ID,CUST_SOURCE_REF_ID
FROM CUST_REVIEWS reviews
INNER JOIN CUST_DAY0_MERGE merge1
ON (reviews.CUST_SOURCE_REF_ID = merge1.OLD_REF_ID_1)
INNER JOIN CUST_DAY0_MERGE merge2
ON (reviews.CUST_SOURCE_REF_ID = merge2.OLD_REF_ID_2)
INNER JOIN CUST_DAY0_MERGE merge3
ON (reviews.CUST_SOURCE_REF_ID = merge3.OLD_REF_ID_3);

如何通过将CUST_ID 和CUST_SOURCE_UNIQUE_ID 更改为我想要达到的条件来增强插入语句？

Answer 1

“如果满足上述条件，将向 CUST_REVIEWS 插入一条新记录” - 你的意思是

"如果以上至少一项" 或
“如果以上所有”？

在第二种情况下，您可以使用单个连接：

INNER JOIN CUST_DAY0_MERGE merge
ON (reviews.CUST_SOURCE_REF_ID = merge.OLD_REF_ID_1)
AND
(reviews.CUST_SOURCE_REF_ID = merge.OLD_REF_ID_2)
AND
(reviews.CUST_SOURCE_REF_ID = merge.OLD_REF_ID_3)

在第一种情况下，您可以使用“OR”，但使用“UNION”会被报告为更理想：

INNER JOIN CUST_DAY0_MERGE merge
    ON (reviews.CUST_SOURCE_REF_ID = merge.OLD_REF_ID_1)
    OR
    (reviews.CUST_SOURCE_REF_ID = merge.OLD_REF_ID_2)
    OR
    (reviews.CUST_SOURCE_REF_ID = merge.OLD_REF_ID_3)

对比

       INSERT INTO CUST_REVIEWS(CUST_REVIEW_ID,RUN_DATE,CUST_ID,CUST_SOURCE_UNIQUE_ID,CUST_SOURCE_REF_ID)  

       SELECT CUST_REVIEW_ID,RUN_DATE,merge.NEW_CUST_ID as CUST_ID,merge.NEW_CUST_ID as CUST_SOURCE_UNIQUE_ID,CUST_SOURCE_REF_ID
FROM CUST_REVIEWS reviews
       INNER JOIN CUST_DAY0_MERGE merge
           ON (reviews.CUST_SOURCE_REF_ID = merge.OLD_REF_ID_1)

       UNION
       SELECT CUST_REVIEW_ID,RUN_DATE,merge.NEW_CUST_ID as CUST_ID,merge.NEW_CUST_ID as CUST_SOURCE_UNIQUE_ID,CUST_SOURCE_REF_ID
FROM CUST_REVIEWS reviews    
       INNER JOIN CUST_DAY0_MERGE merge
          ON (reviews.CUST_SOURCE_REF_ID = merge.OLD_REF_ID_2)

       UNION
       SELECT CUST_REVIEW_ID,RUN_DATE,merge.NEW_CUST_ID as CUST_ID,merge.NEW_CUST_ID as CUST_SOURCE_UNIQUE_ID,CUST_SOURCE_REF_ID
FROM CUST_REVIEWS reviews    
       INNER JOIN CUST_DAY0_MERGE merge
          ON (reviews.CUST_SOURCE_REF_ID = merge.OLD_REF_ID_3)