與Squeel

Question

不用說我有一組條件：

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

...這將生成SQL如下：

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

如何去反向返回集，即更新Squeel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)) 

這是一個小小的設計，因爲我的問題還涉及動態屬特德條件集 - 我不能改變實際條件，但只是需要他們包裝在一個NOT（）。

任何任何想法或建議在哪裏看？

Answer 1

你會想要使用一元減號運算符。

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))))"