需要相关的SQL查询区别为包括和联接

Question

发现策略差异，陈述每个语句的用例，并为两者编写生成的SQL。

users = User.joins(:company).entries
users.each { |u| { email: u.email, company: u.company.name } }

Vs

users = User.includes(:company).entries
users.each { |u| { email: u.email, company: u.company.name } }