SQL Server 2019

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select @@version;


(No column name)


Microsoft SQL Server 2019 (RTM-CU6) (KB4563110) - 15.0.4053.23 (X64) 
	Jul 25 2020 11:26:55 
	Copyright (C) 2019 Microsoft Corporation
	Express Edition (64-bit) on Windows Server 2019 Standard 10.0 <X64> (Build 17763: ) (Hypervisor)



create table #temp(tablename varchar(20),columnname varchar(20));

insert into #temp values
('#CUSTOMERS_MND_0','city'),('#CUSTOMERS_MND_0','county'),('#CUSTOMERS_MND_0','partners'),('#CUSTOMERS_MND_0','product')

4 rows affected

declare @sql varchar(max)
declare @orderby varchar(max)
set @sql = ('select *, row_number() over (partition by unique_key order by ')
set @orderby =(select STRING_AGG(columnname, ' desc,') 
WITHIN GROUP (ORDER BY columnname) from #temp)
set @orderby = concat(@orderby,' desc')
set @sql = concat(@sql,@orderby)
set @sql = concat(@sql,' from ')
set @sql = concat(@sql, (select distinct tablename from #temp),' ')
set @sql = concat(@sql,')select * from cte where rn = 1')

select @sql;
--select @orderby


(No column name)


select *, row_number() over (partition by unique_key order by city desc,county desc,partners desc,product desc from #CUSTOMERS_MND_0 )select * from cte where rn = 1