Query to find distinct comma separated values in Oracle

 

Oracle Query to find distinct comma separated values from given String : 

SELECT Listagg(word, ',')
         within GROUP (ORDER BY NULL) output_string
FROM   (SELECT DISTINCT Regexp_substr(val, '[^,]+', 1, column_value) word
        FROM   (SELECT :p_comma_seperated_str val
                FROM   dual),
               TABLE(Cast(MULTISET(SELECT LEVEL
                             FROM   dual
                             CONNECT BY LEVEL <= Regexp_count(val, ',') + 1) AS
                          sys.ODCINUMBERLIST)));