title: Oracle SQL listagg multiple column in one column
body: <p>I have this following db with query and result <a href="https://prnt.sc/iyq1en" rel="nofollow noreferrer">image</a>
  but as you can see there are mutiple times returned the same name it should look like Rob, Rose, Will and thats it. What should i do to reach this goal? Is there anything wrong in my query?</p>
  
  <pre><code>SELECT FILM.NAZEV, FILM.VYDANI, FILM.DELKA, FILM.CENA, LISTAGG(OSOBA.JMENO, ',') WITHIN GROUP (ORDER BY OSOBA.JMENO) AS ProdukceFROM FILM_PRODEJNA
  INNER JOIN FILM ON FILM_PRODEJNA.FILM_ID_FILM = FILM.ID_FILM
  LEFT JOIN FILM_PRODUKCE ON FILM_PRODUKCE.FILM_ID_FILM = FILM.ID_FILM
  LEFT JOIN PRODUKCE ON PRODUKCE.ID_PRODUKCE = FILM_PRODUKCE.ID_FILM_PRODUKCE
  LEFT JOIN ZASTOUPENI ON ZASTOUPENI.ID_ZASTOUPENI = PRODUKCE.ID_PRODUKCE
  LEFT JOIN OSOBA ON ZASTOUPENI.OSOBA_ID_OSOBA = OSOBA.ID_OSOBA GROUP BY FILM.NAZEV, FILM.VYDANI, FILM.DELKA, FILM.CENA;
  </code></pre>