Lustra::View

Create and maintain your database views directly in the code.

You could use the migration system to create and drop your views. However this is proven to be difficult, even more if you want to update a view which depends on another subviews.

How it works ?

When you migrate using the migration system, all the views registered are going to be destroyed and recreated again. Order of creation depends of the requirement for each views

Example

Lustra::View.register :room_per_days do |view|
  view.require(:rooms, :year_days)

  view.query <<-SQL
    SELECT room_id, day
    FROM year_days
    CROSS JOIN rooms
  SQL
end

Lustra::View.register :rooms do |view|
  view.query <<-SQL
  SELECT room.id AS room_id
  FROM generate_series(1, 4) AS room(id)
  SQL
end

Lustra::View.register :year_days do |view|
  view.query <<-SQL
  SELECT date.day::date AS day
  FROM   generate_series(
    date_trunc('day', NOW()),
    date_trunc('day', NOW() + INTERVAL '364 days'),
    INTERVAL '1 day'
  ) AS date(day)
  SQL
end

In the example above, room_per_days will be first dropped before a migration start and last created after the migration finished, to prevent issue where some views are linked to others