Question

I have some strings that have a version number at the end of the string. I need to sort them.

i.e.

1
5
6
L1
L2
L123
L300
L500
L123.5
L300.5

If I exclude the .x rows I can get these to sort using LPAD but the version number is stumping me. Looking to get the data to be interpreted as follows so I can sort correctly but I am failing miserably.

0001.00
0005.00
0006.00
00L1.00
00L2.00
L123.00
L300.00
L500.00
L123.50
L300.50

Answer 1

Assuming that the length of version number is the same, the following will give you what you are looking for:

use DBName;
create table versions(
   Id int not null auto_increment,
   primary key(Id),
   ver varchar(20) not null
)TYPE=MyISAM;

insert into versions(ver) values('1');
insert into versions(ver) values('5');
insert into versions(ver) values('6');
insert into versions(ver) values('L1');
insert into versions(ver) values('L2');
insert into versions(ver) values('L123');
insert into versions(ver) values('L300');
insert into versions(ver) values('L500');
insert into versions(ver) values('L123.5');
insert into versions(ver) values('L300.5');

Select CONCAT( LPAD(ver, 4, '0'), 
               Case 
                    When dot ='.' 
                    Then CONCAT('.', SUBSTRING(ver, 6, 1), '0') 
               Else '.00' 
               End
              ) VersionNumber
From
(
   Select ver, SUBSTRING(ver,5,1) dot From versions
) as sub
Order by VersionNumber;

This willl gives you:

0001.00
0005.00
0006.00
00L1.00
00L2.00
L123.00
L123.50
L300.00
L300.50
L500.00