How do you sort a text field with numeric data in numeric order

Question

We have a text field (varchar2) that has numeric data. When we sort it the items display as
1
2
3
4
5
6
7
8
9
10
*101*
12
Instead of
1
2
3
4
5
6
7
8
9
10
12
101
How can I make it display in numeric order if the field is a varchar2
Howard

Answer 1

To avoid string-to-number conversion:
SQL> with t as (
  2  select '1' a from dual union
  3  select '2' a from dual union
  4  select '3' a from dual union
  5  select '4' a from dual union
  6  select '5' a from dual union
  7  select '6' a from dual union
  8  select '7' a from dual union
  9  select '8' a from dual union
10  select '9' a from dual union
11  select '10' a from dual union
12  select '101' a from dual union
13  select '12' a from dual)
14  select a from t
15  order by length(a), a;
A
1
2
3
4
5
6
7
8
9
10
12
101
12 rows selected.Max
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