有条件的在哪里？

Question

使用以下table。我正在尝试获取 Party_ID。我将只有 NEW_ORG_ID 和 ORIGINAL_ID。

使用 NEW_ORG_ID 我想得到 PARTY_ID 与 MAX(USR_CRTE_TS) unless ORIGINAL_ID 匹配以及。然后我想要 PARTY_ID 其中 NEW_ORG_ID 和 ORIGINAL_ID 匹配。

PARTY_ID          |DIRS_ID  |SUPPLIER_ID|ORIGINAL_ID|TRIANGLE_ID|NEW_ORG_ID|USR_CRTE_TS        |
------------------|---------|-----------|-----------|-----------|----------|-------------------|
5385606962        |476800490|5385606962 |NULL       |NULL       |69214683  |2018-09-27 04:56:13|
69214683          |476800490|NULL       |2740793553 |NULL       |69214683  |2018-09-27 04:54:15|

我尝试了以下方法。请记住，我仅针对此示例对 NEW_ORG_ID 和 ORIGINAL_ID 进行了硬编码。在现实世界中，NEW_ORG_ID 和 ORIGINAL_ID 由查询的另一部分提供。

    SELECT DISTINCT PARTY_ID 
FROM UNIQUE_IDS UNQ 
WHERE   
( 
        CASE
            WHEN ( 
                    SELECT ts.PARTY_ID
                    FROM UNIQUE_IDS ts 
                    WHERE (ts.NEW_ORG_ID = '69214683' AND ts.ORIGINAL_ID = '2740793553') 
                 ) IS NOT NULL
            THEN 
                (
                    SELECT ts.PARTY_ID 
                    FROM UNIQUE_IDS ts 
                    WHERE (ts.NEW_ORG_ID = '69214683' AND ts.ORIGINAL_ID = '2740793553') 
                )
            ELSE 
                (
                    SELECT ts.PARTY_ID
                    FROM UNIQUE_IDS ts 
                    WHERE ts.NEW_ORG_ID = '69214683'
                    AND ts.USR_CRTE_TS = (  
                                            SELECT MAX(ts.USR_CRTE_TS) 
                                            FROM UNIQUE_IDS ts 
                                            WHERE ts.NEW_ORG_ID = '69214683'
                                        )--xref.SBL_GLOB_CSTMR_ID)
                )
        END
) = UNQ.NEW_ORG_ID

;

Answer 1

我会使用 row_number() 和条件排序：

select party_id 
  from (
    select party_id, 
           row_number() over (order by case when original_id = '2740793553' then 1 end, 
                                       usr_crte_ts desc) rn
      from unique_ids unq
      where new_org_id = '69214683')
  where rn = 1

^{dbfiddle demo}

如果 original_id 匹配，则行具有更高的优先级。第二优先级最高 usr_crte_ts。最后我们拿下最好的一排。

Answer 2

可以用ROW_NUMBER()解析函数得到标号为1的"best"匹配（先用ORIGINAL_ID，再用USR_CRTE_TS），过滤关于：

SELECT PARTY_ID
FROM   (
            SELECT  PARTY_ID,
                    USR_CRTE_TS,  
                    ROW_NUMBER() OVER (
                        PARTITION BY PARTY_ID 
                        ORDER BY     CASE ORIGINAL_ID 
                                         WHEN '2740793553' THEN 0 
                                         ELSE 1 
                                     END,
                                     USR_CRTE_TS DESC
                    ) RN
            FROM    UNIQUE_IDS
            WHERE   NEW_ORG_ID = '69214683'
        )
WHERE   RN = 1

如果USR_CRTE_TS可以是NULL，那么在最后再添加一个条件来符合你的条件：

AND     (ORIGINAL_ID = '2740793553' OR USR_CRTE_TS IS NOT NULL)

当标准在别处select编辑时

您可以使用 WITH 子句逐层构建查询。因此，让我们假设您已经有了 select 两个 "parameters" 的工作逻辑，然后将其放入 with 子句中，如下所示：

WITH CRIT(SEL_ORG_ID, SEL_ORIGINAL_ID) AS (
    SELECT '69214683', '2740793553' FROM DUAL -- this is just an example
)

...然后像这样继续查询：

), BASE AS (
    SELECT  UI.PARTY_ID,
            UI.USR_CRTE_TS,
            UI.ORIGINAL_ID,
            CRIT.SEL_ORIGINAL_ID,
            ROW_NUMBER() OVER (
                PARTITION BY UI.PARTY_ID 
                ORDER BY     CASE UI.ORIGINAL_ID 
                                 WHEN CRIT.SEL_ORIGINAL_ID THEN 0 
                                 ELSE 1 
                             END,
                             UI.USR_CRTE_TS DESC
            ) RN
    FROM    UNIQUE_IDS UI,
            CRIT
    WHERE   UI.NEW_ORG_ID = CRIT.SEL_NEW_ORG_ID
)
SELECT PARTY_ID
FROM   BASE
WHERE  RN = 1
AND    (ORIGINAL_ID = SEL_ORIGINAL_ID OR USR_CRTE_TS IS NOT NULL)

有条件的在哪里？

Conditional Where?

sql

oracle

case

where

当标准在别处select编辑时