Xml

[captainkirk]

Hello everybody

I have a table like this
1,red
1,black
1,red
2,red
2,yellow
2,green
2,red

with this Query
select num ,
xmlserialize(co ntent xmlagg(
xmlelement(name "color", color))
as varchar(1024))
from table
group by num


I obtain
1 red, black, red
2 red, yellow, green, red

How can I obtain a unique list of colors, like this (of course without any stored procedure)
1 red, black
2 red, yellow, green,

thanks