tx := db.Begin()
	defer func() {
		if r := recover(); r != nil {
			tx.Rollback()
		}
	}()
	if err := tx.Error; err != nil {
		t.Errorf("Failed to start transaction, got error %v\n", err)
	}

	if err := tx.Where("name=?", "zzjin").Delete(&User{}).Error; err != nil {
		tx.Rollback()
		t.Errorf("Failed to run one transaction, got error %v\n", err)
	}

		sql = numericPlaceholder.ReplaceAllString(sql, "$$$1$$")

		sql = numericPlaceholderRe.ReplaceAllStringFunc(sql, func(v string) string {
			num := v[1 : len(v)-1]
			n, _ := strconv.Atoi(num)

			// position var start from 1 ($1, $2)
			n -= 1
			if n >= 0 && n <= len(vars)-1 {
				return vars[n]
			}
			return v
		})
	}

	return sql