CONCAT strings from multiple rows in one SELECT

I'd like to be able to return a single cell containing a string formed from all the records in a table, ie

mysql> SELECT OrganisationName FROM t1;
+------------------+
| OrganisationName |
+------------------+
| this |
| that |
| the other |
+------------------+

I want this:

+-----------------------+
| SomeSelectFunction |
+-----------------------+
| this, that, the other |
+-----------------------+

Probably will have to use a stored function. Something like:

Code:

---

declare
  lAnswer varchar2(2222);
begin
  for x in (select rownum, OrganisationName from t1) loop
    if x.rownum = 1 then
      lAnswer := x.OrganisationName;
    else
      lAnswer := lAnswer || ', ' || x.OrganisationName;
    end if;
  end loop;
  return lAnswer;
end;
/

---

No other choice to get it done with a single querry

Sure, by using DECODE or CASE, but only if you know in advance how many records there are in a table...