试图逆WHERE子句，但它不加起来

Question

我运行一个SQL查询，告诉我一些表结果。没有WHERE子句的查询返回结果1087

SELECT hf.id, hf.`nhs_choices_organisationid`,hf.`sites_organisation_code`,hf.`eric_site_id` FROM `hospital_final` hf
left join nhs_choices nc on nc.OrganisationID = hf.`nhs_choices_organisationid`
left join sites s on s.`Organisation Code` = hf.`sites_organisation_code`
left join eric_site es on es.site_code = hf.`sites_organisation_code`

如果我添加在WHERE子句中，我得到260个结果

SELECT hf.id, hf.`nhs_choices_organisationid`,hf.`sites_organisation_code`,hf.`eric_site_id` FROM `hospital_final` hf
left join nhs_choices nc on nc.OrganisationID = hf.`nhs_choices_organisationid`
left join sites s on s.`Organisation Code` = hf.`sites_organisation_code`
left join eric_site es on es.site_code = hf.`sites_organisation_code`
WHERE (REPLACE( (REPLACE( s.NAME, "'", '')), " ", '')) LIKE (REPLACE( (REPLACE( nc.OrganisationName, "'", '')), " ", ''))AND  (REPLACE( (REPLACE( nc.OrganisationName, "'", '')), " ", '')) LIKE (REPLACE( (REPLACE( es.site_name, "'", '')), " ", ''))

现在我想做的是找到所有未在where子句中的结果。我的第一个明显的解决方案是围绕在支架和不带它的前缀

SELECT hf.id, hf.`nhs_choices_organisationid`,hf.`sites_organisation_code`,hf.`eric_site_id` FROM `hospital_final` hf
left join nhs_choices nc on nc.OrganisationID = hf.`nhs_choices_organisationid`
left join sites s on s.`Organisation Code` = hf.`sites_organisation_code`
left join eric_site es on es.site_code = hf.`sites_organisation_code`
WHERE NOT ((REPLACE( (REPLACE( s.NAME, "'", '')), " ", '')) LIKE (REPLACE( (REPLACE( nc.OrganisationName, "'", '')), " ", ''))AND  (REPLACE( (REPLACE( nc.OrganisationName, "'", '')), " ", '')) LIKE (REPLACE( (REPLACE( es.site_name, "'", '')), " ", '')))

但是，这只是返回370个结果

我试图做它明确这个时候

SELECT hf.id, hf.`nhs_choices_organisationid`,hf.`sites_organisation_code`,hf.`eric_site_id` FROM `hospital_final` hf
left join nhs_choices nc on nc.OrganisationID = hf.`nhs_choices_organisationid`
left join sites s on s.`Organisation Code` = hf.`sites_organisation_code`
left join eric_site es on es.site_code = hf.`sites_organisation_code`
WHERE (REPLACE( (REPLACE( s.NAME, "'", '')), " ", ''))  NOT LIKE (REPLACE( (REPLACE( nc.OrganisationName, "'", '')), " ", ''))OR  (REPLACE( (REPLACE( nc.OrganisationName, "'", '')), " ", '')) NOT LIKE (REPLACE( (REPLACE( es.site_name, "'", '')), " ", ''))OR (REPLACE( (REPLACE( es.site_name, "'", '')), " ", '')) NOT LIKE (REPLACE( (REPLACE( s.NAME, "'", '')), " ", ''))

并再次只得到370。

现在，根据我的数学1087-260≠370的基本原理的理解。

我可以把它全部写出来进入返回预期的827，但必要的子查询？

SELECT hf.id, hf.`nhs_choices_organisationid`,hf.`sites_organisation_code`,hf.`eric_site_id` FROM `hospital_final` hf
left join nhs_choices nc on nc.OrganisationID = hf.`nhs_choices_organisationid`
left join sites s on s.`Organisation Code` = hf.`sites_organisation_code`
left join eric_site es on es.site_code = hf.`sites_organisation_code`
WHERE hf.id NOT IN
(SELECT hf.id FROM `hospital_final` hf
left join nhs_choices nc on nc.OrganisationID = hf.`nhs_choices_organisationid`
left join sites s on s.`Organisation Code` = hf.`sites_organisation_code`
left join eric_site es on es.site_code = hf.`sites_organisation_code`
WHERE (REPLACE( (REPLACE( s.NAME, "'", '')), " ", ''))  LIKE (REPLACE( (REPLACE( nc.OrganisationName, "'", '')), " ", ''))AND  (REPLACE( (REPLACE( nc.OrganisationName, "'", '')), " ", '')) LIKE (REPLACE( (REPLACE( es.site_name, "'", '')), " ", '')))

Answer 1

你有一些复杂的WHERE表达，但这并不重要。什么是重要的是，的倒数：

WHERE <something>

不是

WHERE NOT <something>

这是因为表达式可以计算为NULL - 这是尤其如此，与外部连接。

正确的反应该是：

WHERE (NOT <something> OR
       <something> IS NULL
      )