log.Println("testing tidb...")
		if dbDSN == "" {
			dbDSN = tidbDSN
		}
		db, err = gorm.Open(mysql.Open(dbDSN), cfg)
	default:
		log.Println("testing sqlite3...")
		db, err = gorm.Open(sqlite.Open(filepath.Join(os.TempDir(), "gorm.db")), cfg)
		if err == nil {
			db.Exec("PRAGMA foreign_keys = ON")
		}
	}

	if err != nil {
		return
	}

	if debug := os.Getenv("DEBUG"); debug == "true" {