Drupal Search function in custom module
You have few options:


Use hook_views_data() to hook your custom tables with Views.
Use Data module as it features automatic integration with Views.
Reorder your setup to use Drupal's node type/user profile/entity, which has Views support out of the box.


Doing it really manually will be a waste of time, unless you need some very specific functionality that can be hardly achieved by using Views for it.

Views will also provide you with caching, paging and it will be easier to maintain it in the future.