postgresql的两个NOT-LIKE子句返回错误的结果

合并时 NOT LIKE 然后 AND OR

select distinct pcl_mun 
from exemptions.modiv_parcels_2015 
where pcl_mun NOT LIKE '10%' 
  AND pcl_mun NOT LIKE '18%'
order by pcl_mun

这是一件合乎逻辑的事情,有时会让人困惑。

简化示例:

('18' NOT LIKE '10%') OR ('18' NOT LIKE '18%')  --> true OR false --> true
('18' NOT LIKE '10%') AND ('18' NOT LIKE '18%')  --> true AND false --> FALSE

('14' NOT LIKE '10%') OR ('14' NOT LIKE '18%')  --> true OR true --> TRUE
('14' NOT LIKE '10%') AND ('14' NOT LIKE '18%')  --> true AND true --> TRUE

因为否定两个词的组合是不同的 LIKE
那么 或者

NOT ('18' LIKE '10%' OR '18' LIKE '18%')  --> NOT(false OR true) --> FALSE
NOT ('18' LIKE '10%' AND '18' LIKE '18%')  --> NOT(false AND true) --> true

NOT ('14' LIKE '10%' OR '14' LIKE '18%')  --> NOT(false OR false) --> TRUE
NOT ('14' LIKE '10%' AND '14' LIKE '18%')  --> NOT(false AND false) --> TRUE