Question

我在这里很困惑第一个sql -

我的cnt_content表中有一个条目content_pk=5419441和title=test wls-2

现在我正在运行这个sql 1 -

SELECT
   title,
   content_pk 
FROM
   cnt_content c 
WHERE
   c.type not in (
      'AMT', 'LPA', 'QUE'
   ) 
   AND c.private_flag = 'N' 
   AND c.searchable_flag = 'Y' 
   AND c.status in (
      'PUB', 'NAP'
   ) 
   AND (
      trim(c.title) LIKE 'test wls-2' 
      OR trim(c.special_keyword) LIKE 'test wls-2'
   )  
   and not exists (
      SELECT
         1 
      FROM
         cmd_content_metadata cmd 
      WHERE
         cmd.content_pk=5419441 
         AND cmd.for_others='Y' 
   )  
ORDER BY
   c.last_modified_date desc;

正在给出结果 - content_pk=5419441和title=test wls-2

但是当我运行这个sql 2 -

时

SELECT
   title,
   content_pk 
FROM
   cnt_content c 
WHERE
   c.type not in (
      'AMT', 'LPA', 'QUE'
   ) 
   AND c.private_flag = 'N' 
   AND c.searchable_flag = 'Y' 
   AND c.status in (
      'PUB', 'NAP'
   ) 
   AND (
      trim(c.title) LIKE 'test wls-2' 
      OR trim(c.special_keyword) LIKE 'test wls-2'
   )  
   and not exists (
      SELECT
         1 
      FROM
         cmd_content_metadata cmd 
      WHERE
         cmd.content_pk=c.content_pk 
         AND cmd.for_others='Y' 
   )  
ORDER BY
   c.last_modified_date desc;

没有给出任何结果。任何人请解释。

Answer 1

因为在一个中你只是将content_pk的特定值赋予5419441，而另一个使用核心查询，这意味着对于在外部查询中选择的content_pk的每个值，您在子选择查询中检查是否相等

为什么两个sql给出不同的结果？

1 个答案: