如果指定了SELECT DISTINCT，则ORDER BY项目必须出现在选择列表中

我将选择列表中的列添加到按列表排序，但是它仍然给我错误：

如果指定了SELECT DISTINCT，则ORDER BY项目必须出现在选择列表中。

这是存储的过程：

CREATE PROCEDURE [dbo].[GetRadioServiceCodesINGroup] @RadioServiceGroup nvarchar(1000) = NULL AS BEGIN SET NOCOUNT ON;

SELECT DISTINCT rsc.RadioServiceCodeId, rsc.RadioServiceCode + ' - ' + rsc.RadioService as RadioService FROM sbi_l_radioservicecodes rsc INNER JOIN sbi_l_radioservicecodegroups rscg ON rsc.radioservicecodeid = rscg.radioservicecodeid WHERE rscg.radioservicegroupid IN (select val from dbo.fnParseArray(@RadioServiceGroup,',')) OR @RadioServiceGroup IS NULL
ORDER BY rsc.RadioServiceCode,rsc.RadioServiceCodeId,rsc.RadioService

END

问题来源于stack overflow