# File lib/dm-constraints/adapters/dm-do-adapter.rb, line 41
        def create_relationship_constraint(relationship)
          return false unless valid_relationship_for_constraint?(relationship)

          source_model = relationship.source_model
          source_table = source_model.storage_name(name)
          source_key   = relationship.source_key

          constraint_name = constraint_name(source_table, relationship.name)
          return false if constraint_exists?(source_table, constraint_name)

          constraint_type = case relationship.inverse.constraint
            when :protect            then 'NO ACTION'
            when :destroy, :destroy! then 'CASCADE'
            when :set_nil            then 'SET NULL'
          end

          return false if constraint_type.nil?

          storage_name           = relationship.source_model.storage_name(name)
          reference_storage_name = relationship.target_model.storage_name(name)

          foreign_keys   = relationship.source_key.map { |p| property_to_column_name(p, false) }
          reference_keys = relationship.target_key.map { |p| property_to_column_name(p, false) }

          execute(create_constraints_statement(storage_name, constraint_name, constraint_type, foreign_keys, reference_storage_name, reference_keys))
        end