ORDER BY using a Non-SELECT list column

Question

I need to SELECT DISTINCT values from a column and ORDER it by another column in the same table which is not in the SELECT list. When i got
ORA-01791: not a SELECTed expression error, I tried various things like putting ORDER BY clause in the outer query, using a DISTINCT in the ORDER BY clause,..etc but couldn't succeed.
SQL> create table sample_table (col1 number, col2 number);
Table created.
SQL> select distinct(col1)
  2  from sample_table
  3  order by col2;
order by col2
ERROR at line 3:
ORA-01791: not a SELECTed expression
SQL> select col1 from
  2  (select distinct(col1) col1 from sample_table)
  3  order by col2;
order by col2
ERROR at line 3:
ORA-00904: "COL2": invalid identifier
SQL> select distinct(col1) col1 from sample_table
  2  order by distinct(col2);
order by distinct(col2)
ERROR at line 2:
ORA-00936: missing expressionAny workarounds for this seemingly simple requirement?

Answer 1

Any workarounds for this seemingly simple requirement?This is not a simple requirement. It is a self contradictory requirement.
You want to order an result on a attribute that you don't have. This is not possible from a logical point of view.
Like saying,
"I want the typical/distinct family size in houses in my town, ordered by house number."