How to check if line exists

Question

Is there a way to check if there is already a line with the same entries?

             ID            |     Name1               |      Name2           
     ______________________|_________________________|_______________________
              1            |     peter               |      hannah           
  ->          2            |     karl                |      claudia           
              3            |     ted                 |      robin           
              4            |     peter               |      bruce           
              5            |     anna                |      luke
  ->          6            |     karl                |      claudia

So that for example, when line two exists, line six can't be written? I think

validates uniqueness

won't work because it's a many to many relation.

Answer 1

Try this instead

validates_uniqueness_of :Name1, :scope => :Name2