在与 CASE 一起使用 THEN 语句后返回超过 1 个值

Posted 2023-05-09

【中文标题】在与 CASE 一起使用 THEN 语句后返回超过 1 个值

【英文标题】：return more than 1 value after THEN statement used with CASE

【发布时间】：2012-10-19 03:26:03

【问题描述】：

以下是我的查询：

UPDATE DSOPI_PERSON_ADDR_RULE ADDR
SET ADDR.DEPT_NAME =
  CASE
    WHEN regexp_like (UPPER(addr.src_address_line1),     'DEP|DPT$|ABT|DIP.|DIPART|AFDEL|AVDEL|AVD.|DIV|PGRD|PGP|PPG')
    AND ADDR.ORG_NAME IS NOT NULL
    THEN ADDR.SRC_ADDRESS_LINE1
    WHEN regexp_like (UPPER(addr.src_address_line2), 'DEP|DPT$|ABT|DIP.|DIPART|AFDEL|AVDEL|AVD.|DIV|PGRD|PGP|PPG')
    AND ADDR.ORG_NAME IS NOT NULL
    THEN ADDR.SRC_ADDRESS_LINE2
    WHEN regexp_like (UPPER(addr.src_address_line3), 'DEP|DPT$|ABT|DIP.|DIPART|AFDEL|AVDEL|AVD.|DIV|PGRD|PGP|PPG')
    AND ADDR.ORG_NAME IS NOT NULL
    THEN ADDR.SRC_ADDRESS_LINE3
    WHEN regexp_like (UPPER(addr.src_address_line4), 'DEP|DPT$|ABT|DIP.|DIPART|AFDEL|AVDEL|AVD.|DIV|PGRD|PGP|PPG')
    AND ADDR.ORG_NAME IS NOT NULL
    THEN ADDR.SRC_ADDRESS_LINE4
    ELSE NULL
 END;

我想做的是，当 case 条件为真时，我想让相应的地址行为 NULL。有没有办法用这段代码实现它？

【参考方案1】：

您可以选择为每个地址字段添加额外的CASE 语句：

代码是重复的，但这允许您在满足条件时将地址行设置为空。

UPDATE DSOPI_PERSON_ADDR_RULE ADDR
SET ADDR.DEPT_NAME =
   CASE
      WHEN regexp_like (UPPER(addr.src_address_line1),
         'DEP|DPT$|ABT|DIP.|DIPART|AFDEL|AVDEL|AVD.|DIV|PGRD|PGP|PPG')
         AND ADDR.ORG_NAME IS NOT NULL
         THEN ADDR.SRC_ADDRESS_LINE1
      WHEN regexp_like (UPPER(addr.src_address_line2), 
         'DEP|DPT$|ABT|DIP.|DIPART|AFDEL|AVDEL|AVD.|DIV|PGRD|PGP|PPG')
         AND ADDR.ORG_NAME IS NOT NULL
         THEN ADDR.SRC_ADDRESS_LINE2
      WHEN regexp_like (UPPER(addr.src_address_line3), 
         'DEP|DPT$|ABT|DIP.|DIPART|AFDEL|AVDEL|AVD.|DIV|PGRD|PGP|PPG')
         AND ADDR.ORG_NAME IS NOT NULL
         THEN ADDR.SRC_ADDRESS_LINE3
      WHEN regexp_like (UPPER(addr.src_address_line4), 
         'DEP|DPT$|ABT|DIP.|DIPART|AFDEL|AVDEL|AVD.|DIV|PGRD|PGP|PPG')
         AND ADDR.ORG_NAME IS NOT NULL
         THEN ADDR.SRC_ADDRESS_LINE4
      ELSE NULL
   END
   , ADDR.SRC_Address_Line1 =
        CASE
           WHEN regexp_like (UPPER(addr.src_address_line1),     
              'DEP|DPT$|ABT|DIP.|DIPART|AFDEL|AVDEL|AVD.|DIV|PGRD|PGP|PPG')
              AND ADDR.ORG_NAME IS NOT NULL
              THEN NULL
           ELSE ADDR.SRC_Address_Line1
        END
   , ADDR.SRC_Address_Line2 =
        CASE
           WHEN regexp_like (UPPER(addr.src_address_line2),     
              'DEP|DPT$|ABT|DIP.|DIPART|AFDEL|AVDEL|AVD.|DIV|PGRD|PGP|PPG')
              AND ADDR.ORG_NAME IS NOT NULL
              THEN NULL
           ELSE ADDR.SRC_Address_Line2
        END
   , ADDR.SRC_Address_Line3 =
        CASE
           WHEN regexp_like (UPPER(addr.src_address_line3),      
              'DEP|DPT$|ABT|DIP.|DIPART|AFDEL|AVDEL|AVD.|DIV|PGRD|PGP|PPG')
              AND ADDR.ORG_NAME IS NOT NULL
              THEN NULL
           ELSE ADDR.SRC_Address_Line3
        END
   , ADDR.SRC_Address_Line4 =
        CASE
           WHEN regexp_like (UPPER(addr.src_address_line4),     
              'DEP|DPT$|ABT|DIP.|DIPART|AFDEL|AVDEL|AVD.|DIV|PGRD|PGP|PPG')
              AND ADDR.ORG_NAME IS NOT NULL
              THEN NULL
           ELSE ADDR.SRC_Address_Line4
        END;

【讨论】：

只是想一想：这种方法执行查询不会花费两倍的时间吗？

您必须在您的环境中进行测试。我通常在 SQL Server 中，并且类似的操作（ORDER BY 中的 CASE 语句）不会在查询中多次计算，所以我希望 Oracle 的行为类似。

【参考方案2】：

所以如果第一个 WHEN 条件为真，您想将 src_address_line1 设置为 NULL，等等？在这种情况下，我会这样做：

UPDATE DSOPI_PERSON_ADDR_RULE ADDR

SET 
addr.src_address_line1 = 
CASE WHEN regexp_like (UPPER(addr.src_address_line1), 'DEP|DPT$|ABT|DIP.|DIPART|AFDEL|AVDEL|AVD.|DIV|PGRD|PGP|PPG') 
AND ADDR.ORG_NAME IS NOT NULL 
THEN NULL ELSE addr.src_address_line1 END, 

addr.src_address_line2 = 
CASE WHEN regexp_like (UPPER(addr.src_address_line2), 'DEP|DPT$|ABT|DIP.|DIPART|AFDEL|AVDEL|AVD.|DIV|PGRD|PGP|PPG') 
AND ADDR.ORG_NAME IS NOT NULL 
THEN NULL ELSE addr.src_address_line2 END, 

addr.src_address_line3 = 
CASE WHEN regexp_like (UPPER(addr.src_address_line3), 'DEP|DPT$|ABT|DIP.|DIPART|AFDEL|AVDEL|AVD.|DIV|PGRD|PGP|PPG') 
AND ADDR.ORG_NAME IS NOT NULL 
THEN NULL ELSE addr.src_address_line3 END, 

addr.src_address_line4 = 
CASE WHEN regexp_like (UPPER(addr.src_address_line4), 'DEP|DPT$|ABT|DIP.|DIPART|AFDEL|AVDEL|AVD.|DIV|PGRD|PGP|PPG') 
AND ADDR.ORG_NAME IS NOT NULL 
THEN NULL ELSE addr.src_address_line4 END;