How to use distinct while using a select that builds xml?

Question

Hi.
Example:
SELECT
XMLELEMENT("Column1" value1
,"Column2" value2
,"Column3" value3
FROM a_table A
Where id_val = x
Imagine that this repeats a same result 4 times. If it was a simple query distinct would work...how can i use distinct with this?
Thanks.
Cheers!

Answer 1

Hi,
what about group by
SQL> WITH A AS(SELECT 1 val1,2 val2,3 val3 FROM dual UNION ALL
  2            SELECT 1     ,2     ,3      FROM dual UNION ALL
  3            SELECT 1     ,2     ,3      FROM dual)
  4  SELECT XMLElement("cols"
  5           ,XMLElement("col1",val1)
  6           ,XMLElement("col2",val2)
  7           ,XMLElement("col3",val3))
  8  FROM A
  9  GROUP BY val1,val2,val3;
XMLELEMENT("COLS",XMLELEMENT("COL1",VAL1),XMLELEMENT("COL2",VAL2),XMLELEMENT("CO
<cols><col1>1</col1><col2>2</col2><col3>3</col3></cols>