Sql 计算一行中小数四舍五入到2位的值的百分比

我有一个查询，它为我提供了列中空值的百分比：

SELECT
  Count(*)
FROM
  XYZ_Referrals
WHERE
  referral_source IS NULL
) * 100.0 / (
  Select
    Count(*)
  From
    XYZ_Referrals
) as 'referral source fields that are populated'

但是，我需要将该值四舍五入并截断到小数点后2位。以下查询循环，但不截断：

SELECT
  Round
    (
        (
            (
                SELECT
                    Count(*)
                FROM
                    XYZ_Referrals
                WHERE
                    referral_source IS NULL
            )
        * 100.0 / Count(*)
        ),2,2
    )
    as 'referral source fields that are populated'
FROM
  XYZ_Referrals

返回的值为5.60000000000

我试过投，但没有成功

SELECT
    (
        Cast
            (
                Round
                    (
                        (
                            (
                                SELECT
                                    Count(*)
                                FROM
                                    XYZ_Referrals
                                WHERE
                                    referral_source IS NULL
                            )
                            * 100.0 / Count(*)
                        )
                    ),2
                AS DECIMAL(3,2)
            )
    )
    as 'referral source fields that are populated'
FROM
  XYZ_Referrals

---

非常感谢您的帮助。

您的思路正确，但小数点的精度不正确：

SELECT CAST(5.600000000000 AS DECIMAL(10, 2))

这会将数字转换为10位精度，小数点后2位