4

假设我有一组条件:

Person.where{(name =~ 'Ernie%') & (salary < 50000) | (name =~ 'Joe%') & (salary > 100000)}

...这将生成如下 SQL:

SELECT "people".* FROM people
  WHERE ("people"."name" LIKE 'Ernie%' AND "people"."salary" < 50000)
  OR  ("people"."name" LIKE 'Joe%' AND "people"."salary" > 100000)

如何反转返回的集合,即更新 Squeel 以返回以下 sql:

SELECT "people".* FROM people
  WHERE NOT(("people"."name" LIKE 'Ernie%' AND "people"."salary" < 50000)
  OR  ("people"."name" LIKE 'Joe%' AND "people"."salary" > 100000))

这有点做作,因为我的问题还涉及一组动态生成的条件 - 我无法更改实际条件,只需要将它们包装在 NOT() 中。

有人对在哪里看有任何想法或建议吗?

4

1 回答 1

8

您需要使用一元减号运算符。

Person.where{-((name =~ 'Ernie%') & (salary < 50000) | (name =~ 'Joe%') & (salary > 100000))}.to_sql
=> "SELECT \"people\".* FROM \"people\"  WHERE (NOT (((\"people\".\"name\" LIKE 'Ernie%' AND \"people\".\"salary\" < 50000) OR (\"people\".\"name\" LIKE 'Joe%' AND \"people\".\"salary\" > 100000))))" 
于 2012-05-24T15:19:41.620 回答