How to merge rows into one row with separator

I need merge rows into one row for summary of calculation (SQL Server 2014).

My SQL query is:

SELECT 
    [c].[Iso],
    SUM([r].[Quantity]) AS [Quantity],
    SUM([r].[Amount]) AS [Amount]
FROM
    [CarReport].[dbo].[Refuelling] [r]
INNER JOIN 
    [CarReport].[dbo].[Currency] [c] ON [r].[CurrencyId] = [c].[CurrencyId]
WHERE 
    [r].[DataId] = 15
    AND [r].[IsDeleted] = 0
GROUP BY 
    [r].[CurrencyId], [c].[Iso]

Result of this query is:

CZK |   50.00 | 1350,00
EUR |   23.00 | 463,20

I would like to have this result:

CZK/EUR |   50.00/23.00 |   1350,00/463,20

When add new currency (x), the result of new currency must be appended:

CZK/EUR/x | 50.00/23.00/x | 1350,00/463,20/x

Can somebody please help me with this topic?

Many thanks

Answer

Something like this should work with earlier versions of MSSQL as well.

;with subQuery as (
    -- paste your base query here
    -- extend it with one additional column:
    -- ,ROW_NUMBER() OVER (ORDER BY ISO) RowNum
) 
select
    (select stuff((select '/' + convert(nvarchar(max), Iso) from subQuery order by RowNum for xml path('')), 1, 1, '')),
    (select stuff((select '/' + convert(nvarchar(max), Quantity) from subQuery order by RowNum for xml path('')), 1, 1, '')),
    (select stuff((select '/' + convert(nvarchar(max), Amount) from subQuery order by RowNum for xml path('')), 1, 1, ''))