ruby-on-rails - Rails5.2 - Active Record .select() 在调用 .count 时导致错误

Question

如何将另一列添加到范围并仍然能够调用 .count、.find、.where 等。

 User.all.select('users.*,"one" as one').count

结果：

  (1.3ms)  SELECT COUNT(users.*,"one" as one) FROM "users"
Traceback (most recent call last):
        1: from (irb):7
ActiveRecord::StatementInvalid (PG::SyntaxError: ERROR:  syntax error at or near "as")
LINE 1: SELECT COUNT(users.*,"one" as one) FROM "users"
                                   ^
: SELECT COUNT(users.*,"one" as one) FROM "users"

标签： ruby-on-railspostgresqlactiverecordruby-on-rails-5.2

Answer 1

 User.all.select('users.*,"one" as one').count(:all)

和

 User.all.select('users.*,"one" as one').count(:id)

两者都有效，因为它指定了 SQL 代码应该依赖的内容。