Input is:
Section1
Section2
Section3
Section10
Section11
Section1A
Section1B
Section12
Section11A
Section11B
And I want output like:
Section1
Section1A
Section1B
Section2
Section3
Section10
Section11
Section11A
Section11B
Section12
I tried query :
select section_name
from sections
order by length(section_name),section_name
Assuming that the structure of your strings is fixed, as in your example, this could be a way:
SQL> select x,
2 to_number(regexp_substr(x, '[0-9]+')) numericPart,
3 regexp_substr(x, '([0-9]+)([A-Z])', 1, 1, '', 2) optionalChar
4 from (
5 select 'Section1' x from dual union all
6 select 'Section2' from dual union all
7 select 'Section3' from dual union all
8 select 'Section10' from dual union all
9 select 'Section11' from dual union all
10 select 'Section1A' from dual union all
11 select 'Section1B' from dual union all
12 select 'Section12' from dual union all
13 select 'Section11A' from dual union all
14 select 'Section11B' from dual
15 )
16 order by numericPart,
17 optionalChar nulls first
18 ;
X NUMERICPART OPTIONALCHAR
---------- ----------- ----------------------------------------
Section1 1
Section1A 1 A
Section1B 1 B
Section2 2
Section3 3
Section10 10
Section11 11
Section11A 11 A
Section11B 11 B
Section12 12
Here you first order by the numeric part, treating it as number, and then consider the (optional) character after the number.