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Database Views for Read Models

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                  class CreateSnipStatsView < ActiveRecord::Migration[6.1]
  def change
    execute <<~SQL
      CREATE VIEW snip_stats AS
      SELECT s.id AS snip_id,
             s.author_id,
             s.views,
             s.score,
             COUNT(c.id) AS comments
      FROM snips s
      LEFT JOIN comments c ON c.post_type = 'Snip' AND c.post_id = s.id
      GROUP BY s.id;
    SQL
  end
end

                  class SnipStat < ApplicationRecord
  self.table_name = 'snip_stats'

  def readonly?
    true
  end
end

Some read paths want a denormalized shape without materializing a new table. Postgres views are a clean option. Keep the view definition in a migration and map it with a read-only model.

Sarah Chen

More from Sarah Chen

Database Views for Read Models

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More from Sarah Chen