How can I do a rails migration and rails seed

Question

I would like to do a rails migration and a rails seed with this postgresql query. How can I do that ?

DROP TABLE IF EXISTS grid_light;
  CREATE TABLE grid_light AS
  SELECT DISTINCT g.ogc_fid AS id, g.geog4326 AS geog
  FROM grid g, tracks t
  WHERE t.path_buff_geog && g.geog4326 AND ST_Intersects(t.path_buff_geog, g.geog4326);

Answer 1

You should be create a rake task ( exp: create grids.rake in your lib/task )

namespace :grids do
  desc 'explain your rake here'
  task create_grid: :environment do
    drop_sql_cmd = <<-SQL
      DROP TABLE IF EXISTS grid_light;
    SQL

    create_sql_cmd = <<-SQL
      CREATE TABLE grid_light AS
      SELECT DISTINCT g.ogc_fid AS id, g.geog4326 AS geog
      FROM grid g, tracks t
      WHERE t.path_buff_geog && g.geog4326 AND ST_Intersects(t.path_buff_geog, g.geog4326);
    SQL
    ActiveRecord::Base.transaction do
      ActiveRecord::Base.connection.execute(drop_sql_cmd)
      ActiveRecord::Base.connection.execute(create_sql_cmd)
    end
  end
end

and if call rake as

bundle exec rake grids:create_grid