用于更新表但多列的 DB2 case 语句

如何解决用于更新表但多列的 DB2 case 语句

我正在尝试将 4 个单独的更新语句合并为一个更新语句。我没有案例陈述的经验，或者我尝试做的事情是否可行。

关于如何构建这个的任何意见？这是我的尝试，但不起作用。

  UPDATE URL
  SET CONTENT_TITLE =
  CASE
     WHEN ID = ? AND SYstem_UPDATE_REASON = ? AND CONTENT_TITLE IS NOT NULL AND ? NOT BETWEEN 400 AND 599 OR ID = ? AND SYstem_UPDATE_REASON = ? AND CONTENT_TITLE != '' AND ? NOT BETWEEN 400 AND 599 THEN ?
     WHEN ID = ? AND CONTENT_TITLE IS NULL AND ? NOT BETWEEN 400 AND 599 OR ID = ? AND CONTENT_TITLE = '' AND ? NOT BETWEEN 400 AND 599 THEN ?
     WHEN ID = ? AND CONTENT_TITLE IS NOT NULL AND ? BETWEEN 400 AND 599 THEN ?
     WHEN ID = ? AND CONTENT_TITLE IS NULL AND ? BETWEEN 400 AND 599 OR ID = ? AND CONTENT_TITLE = '' AND ? BETWEEN 400 AND 599 THEN ?
  SET CONTENT_DSCR =
  CASE
     WHEN ID = ? AND CONTENT_DSCR IS NULL AND ? NOT BETWEEN 400 AND 599 OR ID = ? AND CONTENT_DSCR = '' AND ? NOT BETWEEN 400 AND 599 THEN ?
     WHEN ID = ? AND CONTENT_TITLE IS NOT NULL AND ? BETWEEN 400 AND 599 THEN ?
  SET SYstem_UPDATE_REASON = 'title and dscr update'
  SET UPDATED_ON = SYSDATE
  END

这是我使用的占位符 (?)：

u.urlId,'title and dscr update',u.statusCode,u.urlId,u.contentTitle,null,u.contentDescription,'title and dscr update'

解决方法

也许它根本没有帮助，但是 - 让我试试（因为小时没有回复）：

我不知道 DB2；如果它的 SQL 与 Oracle 的 SQL 类似，则

CASE 应该有它的 END
整个 SET 语句中只有一个 UPDATE 关键字
逻辑上，当有 OR 时，你应该使用括号（否则你会得到意外结果）

像这样：

UPDATE URL
  SET CONTENT_TITLE =
        CASE
           WHEN     (ID = ? AND SYSTEM_UPDATE_REASON = ?  AND CONTENT_TITLE IS NOT NULL AND ? NOT BETWEEN 400 AND 599) 
                 OR (ID = ? AND SYSTEM_UPDATE_REASON = ?  AND CONTENT_TITLE != ''       AND ? NOT BETWEEN 400 AND 599) THEN ?
           WHEN     (ID = ? AND CONTENT_TITLE IS NULL     AND ? NOT BETWEEN 400 AND 599) 
                 OR (ID = ? AND CONTENT_TITLE = ''        AND ? NOT BETWEEN 400 AND 599) THEN ?
           WHEN      ID = ? AND CONTENT_TITLE IS NOT NULL AND ? BETWEEN 400 AND 599 THEN ?
           WHEN     (ID = ? AND CONTENT_TITLE IS NULL AND ? BETWEEN 400 AND 599) 
                 OR (ID = ? AND CONTENT_TITLE = ''    AND ? BETWEEN 400 AND 599) THEN ?
        END,CONTENT_DSCR =
        CASE
           WHEN    (ID = ? AND CONTENT_DSCR IS NULL AND ? NOT BETWEEN 400 AND 599) 
                OR (ID = ? AND CONTENT_DSCR = ''    AND ? NOT BETWEEN 400 AND 599) THEN ?
           WHEN ID = ? AND CONTENT_TITLE IS NOT NULL AND ? BETWEEN 400 AND 599 THEN ?
        END,SYSTEM_UPDATE_REASON = 'title and dscr update',UPDATED_ON = SYSDATE