-- A5M2で実行時にSQL区切り文字を「;」以外にすること
CREATE PROCEDURE crm_history(target_table VARCHAR(255), target_column VARCHAR(255))
BEGIN
	-- 例外処理
	-- エラーが発生した場合に一時テーブルの削除を実施
	DECLARE EXIT HANDLER FOR SQLEXCEPTION 
		BEGIN
			GET DIAGNOSTICS CONDITION 1
				@error_state = RETURNED_SQLSTATE, @error_msg = MESSAGE_TEXT;
			DROP TEMPORARY TABLE IF EXISTS make_history_tmp;
			SIGNAL SQLSTATE '45000'
				SET MESSAGE_TEXT = @error_msg, MYSQL_ERRNO = @error_state;
		END;

	-- ①-1 Salesforce側で更新されたデータの適用開始日時と適用終了日時を設定する
	SET @new_history_save = '
		UPDATE @@target_table 
		SET
			start_datetime = @@target_column
			, end_datetime = "9999-12-31 00:00:00" 
		WHERE
			start_datetime IS NULL 
			AND end_datetime IS NULL
	';
	SET @new_history_save = REPLACE(@new_history_save, "@@target_table", target_table);
	SET @new_history_save = REPLACE(@new_history_save, "@@target_column", target_column);
	PREPARE new_history_save_stmt from @new_history_save;
	EXECUTE new_history_save_stmt;

	-- ②-1 Salesforce側で更新されたデータを検出用一時テーブルの作成
	SET @make_history_tmp_create = '
		CREATE TEMPORARY TABLE make_history_tmp 
		SELECT
			id
			, MIN(@@target_column) AS min_start_datetime
			, MAX(start_datetime) AS max_start_datetime 
		FROM
			@@target_table 
		WHERE
			end_datetime = "9999-12-31 00:00:00" 
		GROUP BY
			id 
		HAVING
			count(id) = 2
	';
	SET @make_history_tmp_create = REPLACE(@make_history_tmp_create, "@@target_table", target_table);
	SET @make_history_tmp_create = REPLACE(@make_history_tmp_create, "@@target_column", target_column);
	PREPARE make_history_tmp_create_stmt from @make_history_tmp_create;
	EXECUTE make_history_tmp_create_stmt;

	-- ②-2 「②-1」で取得した全件に更新処理を行う
	SET @update_end_datetime = '
		UPDATE @@target_table tt 
			LEFT JOIN make_history_tmp mht 
				ON tt.id = mht.id 
				AND tt.start_datetime = mht.min_start_datetime 
		SET
			start_datetime = mht.max_start_datetime - INTERVAL 1 SECOND 
		WHERE
			mht.id IS NOT NULL
	';
	SET @update_end_datetime = REPLACE(@update_end_datetime, "@@target_table", target_table);
	SET @update_end_datetime = REPLACE(@update_end_datetime, "@@target_column", target_column);
	PREPARE update_end_datetime_stmt from @update_end_datetime;
	EXECUTE update_end_datetime_stmt;

	-- ②-3 「②-1」で作成した一時テーブルを削除する
	DROP TEMPORARY TABLE make_history_tmp;

END