def self.call(connection)
if columns_exist?(connection, :tags, [:version_id, :pacticipant_id]) &&
columns_exist?(connection, :versions, [:id, :pacticipant_id])
connection[:tags].where(pacticipant_id: nil).update(
pacticipant_id: connection[:versions].select(:pacticipant_id)
.where(Sequel[:versions][:id] => Sequel[:tags][:version_id])
)
end
if columns_exist?(connection, :tags, [:version_id, :version_order]) &&
columns_exist?(connection, :versions, [:id, :order])
connection[:tags].where(version_order: nil).update(
version_order: connection[:versions].select(:order)
.where(Sequel[:versions][:id] => Sequel[:tags][:version_id])
)
end
end