mysql - 无法发现这两个查询之间的区别

Question

试图清理一个长查询，我提出了一个修改版本，但现在带有某些参数的旧查询返回 6 行，但我的版本不返回任何行。我一直在努力寻找差异，但找不到任何差异。以下是两个版本中具有相同参数集的 WHERE 子句:

丑陋(但有效)版本:

SELECT ... 
FROM table as a
WHERE 1=1 
and a.title LIKE '%Manager%' 
and a.status='Approved'  
and (a.effected_date<=now()) 
and ( 
    (DATE_ADD(a.effected_date, INTERVAL 30 DAY) >= now() AND a.is_hotjob=0) 
     or 
    (DATE_ADD(a.effected_date, INTERVAL 30 DAY) >= now() AND a.is_hotjob=1)
)

我的清理(但损坏)版本:

SELECT ...
FROM `table`  AS `a`
WHERE CONCAT(`a`.`title`, ' | ', `a`.`job_detail_section`) LIKE '%Manager%' AND 
`a`.`status` = 'Approved' AND 
`a`.`effected_date` <= '2013-12-30' AND 
(`a`.`effected_date` >= '2013-11-30' OR `a`.`is_hotjob` = '1')

Answer 1

你得到了最后一个 AND/OR 倒退:

`a`.`effected_date` <= '2013-12-30' OR 
(`a`.`effected_date` >= '2013-11-30' AND `a`.`is_hotjob` = '1')

编辑:重新格式化后，答案看起来更像是:

SELECT ...
FROM `table`  AS `a`
WHERE CONCAT(`a`.`title`, ' | ', `a`.`job_detail_section`) LIKE '%Manager%' AND 
`a`.`status` = 'Approved' AND 
`a`.`effected_date` <= now() AND 
`a`.`effected_date` >= DATE_ADD(a.effected_date, INTERVAL 30 DAY)

并且可能:

AND `a`.`is_hotjob` IN (0,1)