increment deferrals field when job is deferred

lib/App/Netdisco/DB/Result/DeviceSkip.pm

@@ -18,6 +18,25 @@ __PACKAGE__->add_columns(
   "skipover",
   { data_type => "boolean", is_nullable => 1, default_value => \'false' },
 );
+
 __PACKAGE__->set_primary_key("backend", "device", "action");
 
+__PACKAGE__->add_unique_constraint(
+  device_skip_pkey => [qw/backend device action/]);
+
+=head1 METHODS
+
+=head2 increment_deferrals
+
+Increments the C<deferrals> field in the row, only if the row is in storage.
+There is a race in the update, but this is not worrying for now.
+
+=cut
+
+sub increment_deferrals {
+  my $row = shift;
+  return unless $row->in_storage;
+  return $row->update({ deferrals => ($row->deferrals + 1) });
+}
+
 1;