if isTiDB() {
		t.Skipf("This test case skipped, because of TiDB '%s'", reason)
	}
}

func isTiDB() bool {
	return os.Getenv("GORM_DIALECT") == "tidb"
}

func isMysql() bool {
	return os.Getenv("GORM_DIALECT") == "mysql"
}

func isSqlite() bool {
	return os.Getenv("GORM_DIALECT") == "sqlite"
}

func db(unscoped bool) *gorm.DB {
	if unscoped {
		return DB.Unscoped()
	} else {