假设我有一组条件:
Person.where{(name =~ 'Ernie%') & (salary < 50000) | (name =~ 'Joe%') & (salary > 100000)}...which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-我不能更改实际条件,只需要将它们包装在一个NOT()中。
有没有人有什么建议或者建议去哪里找呢?
发布于 2012-05-24 23:19:42
您将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))))" https://stackoverflow.com/questions/10740033
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