在Rails中，如何获取将数据库字段名称保存为条件的变量？

Question

The following controller code doesn't work. Is there a way?

@m = "jan"
@teams = Team.find(:all, :conditions => ["@m = ?", true], :order => "name asc")

thanks.

Answer 1

如果使用Rails 3.x

@teams = Team.where(@m => true).order("name asc").all

Answer 2

You need to interpolate the string!

@m = "jan"
@teams = Team.find(:all, :conditions => ["#{@m} = ?", true], :order => "name asc")

And by the way, database queries when checking for booleans should use the IS operator

@m = "jan"
@teams = Team.find(:all, :conditions => ["#{@m} IS ?",true], :order => "name asc")