add DB VIEW for deivce links

Netdisco/lib/Netdisco/DB/Result/Virtual/DeviceLinks.pm

@@ -0,0 +1,34 @@
+package Netdisco::DB::Result::Virtual::DeviceLinks;
+
+use strict;
+use warnings;
+
+use base 'DBIx::Class::Core';
+
+__PACKAGE__->table_class('DBIx::Class::ResultSource::View');
+
+__PACKAGE__->table('device_links');
+__PACKAGE__->result_source_instance->is_virtual(1);
+__PACKAGE__->result_source_instance->view_definition(<<ENDSQL
+ SELECT dp.ip AS left_ip, di.ip AS right_ip
+   FROM ( SELECT device_port.ip, device_port.remote_ip
+           FROM device_port
+          WHERE device_port.remote_port IS NOT NULL
+          GROUP BY device_port.ip, device_port.remote_ip
+          ORDER BY device_port.ip) dp
+   LEFT JOIN device_ip di ON dp.remote_ip = di.alias
+  WHERE di.ip IS NOT NULL
+  ORDER BY dp.ip
+ENDSQL
+);
+
+__PACKAGE__->add_columns(
+  'left_ip' => {
+    data_type => 'inet',
+  },
+  'right_ip' => {
+    data_type => 'inet',
+  },
+);
+
+1;