Process sqlite separately

migrate_1.rb

class AddSourceTypeToPermissionTemplates < ActiveRecord::Migration[4.2]
  def self.up
    add_column :permission_templates, :source_type, :string, default: 'admin_set'

    unless connection.adapter_name.downcase.starts_with?('sqlite') && Hyrax::PermissionTemplate.any?
      # if this is not sqlite, then we can simply rename
      # if this is sqlite, we can rename if the table is empty
      rename_column :permission_templates, :admin_set_id, :source_id
    else
      # otherwise, sqlite throws an error when renaming a foreign key that already has values,
      # so we'll add a column and copy the data in.
      # NOTE: The old column :admin_set_id will still exist, but not be used.
      remove_index :permission_template_accesses, :permission_template
      rename_column :permission_templates, :admin_set_id, :source_id

      # add_column :permission_templates, :source_id, :string
      # add_index :permission_templates, :source_id
      # ActiveRecord::Base.connection.execute "UPDATE permission_templates SET source_id = admin_set_id"
    end
  end

  def self.down
    remove_column :permission_templates, :source_type

    unless connection.adapter_name.downcase.starts_with?('sqlite') && Hyrax::PermissionTemplate.any?
      # if this is not sqlite, then we can simply rename
      # if this is sqlite, we can rename if the table is empty
      rename_column :permission_templates, :source_id, :admin_set_id
    else
      # otherwise, sqlite throws an error when renaming a foreign key that already has values,
      # so we'll add a column and copy the data in.
      # NOTE: The old column :admin_set_id will still exist, but not be used.
      remove_column :permission_templates, :source_id
    end
  end
end

class AddSourceTypeToPermissionTemplates < ActiveRecord::Migration[4.2]
  def self.up
    unless connection.adapter_name.downcase.starts_with?('sqlite') && Hyrax::PermissionTemplate.any?
      # if this is not sqlite, then we can simply rename
      # if this is sqlite AND the table is empty, we can rename
      rename_column :permission_templates, :admin_set_id, :source_id
      add_column :permission_templates, :source_type, :string, default: 'admin_set'
    else
      # otherwise, sqlite throws an error when renaming a foreign key that already has values,
      # so we'll rename the table and copy the data into a new version of the table
      rename_table :permission_templates, :permission_templates_copy
      create_table :permission_templates do |t|
        t.string :source_id
        t.string :source_type
        t.string :visibility
        t.timestamps
        t.date :release_date
        t.string :release_period
      end
      add_index :permission_templates, :source_id
      copy_data_up
      # drop_table :permission_templates_copy
    end
  end

  def self.down
    unless connection.adapter_name.downcase.starts_with?('sqlite') && Hyrax::PermissionTemplate.any?
      # if this is not sqlite, then we can simply rename
      # if this is sqlite AND the table is empty, we can rename
      rename_column :permission_templates, :source_id, :admin_set_id
      drop_column :permission_templates, :source_type
    else
      # otherwise, sqlite throws an error when renaming a foreign key that already has values,
      # so we'll rename the table and copy the data into a new version of the table
      rename_table :permission_templates, :permission_templates_copy
      create_table :permission_templates do |t|
        t.string :admin_set_id
        t.string :visibility
        t.timestamps
        t.date :release_date
        t.string :release_period
      end
      add_index :permission_templates, :admin_set_id
      copy_data_down
      # drop_table :permission_templates_copy
    end
  end

  def copy_data_up
    sql_query = "INSERT INTO permission_templates (source_id, source_type, visibility, created_at, updated_at, release_date, release_period)" \
                "SELECT admin_set_id, 'admin_set', visibility, created_at, updated_at, release_date, release_period FROM permission_templates_copy"
    ActiveRecord::Base.connection.execute sql_query
  end

  def copy_data_down
    sql_query = "INSERT INTO permission_templates (admin_set_id, visibility, created_at, updated_at, release_date, release_period)" \
                "SELECT source_id, visibility, created_at, updated_at, release_date, release_period FROM permission_templates_copy"
    ActiveRecord::Base.connection.execute sql_query
  end
end