class AddUniqueIndexToEtablissement < ActiveRecord::Migration[6.1] include Database::MigrationHelpers disable_ddl_transaction! def up delete_duplicates :etablissements, [:dossier_id] remove_index :etablissements, [:dossier_id] add_concurrent_index :etablissements, [:dossier_id], unique: true end def down remove_index :etablissements, [:dossier_id] add_concurrent_index :etablissements, [:dossier_id] end end