Question

I’m looking for a way to order/sort a set of strings that define software versions, in the following format: x.x.x (e.g.: 1.3.12).

Those strings are in an database(mysql) , but I’m not sure if this is even relevant.

One idea I can think of is to make a String ->integer(or float) conversion and than sort the set by the integer index. However I’m not sure if this is possible.

Also I’m looking for other ideas.

Thanks

UPDATE: I just thought about setting a number which represents the maximum version I could implement(and by version I mean major version,minor version, revision). for example I choose the number 300 , so the maximum version will be 299.299.299
so.. when I convert I can do something like this: major*pow(300,2)+minor*pow(300,1)+revision*pow(300,0)

Still opened to ideas.

Answer 1

Don’t use multidotted strings as strings – you’ll have big headache on compare it’s value

In your case you can (must?) expand version to 4-octets string (with trailing 0) and use IP4-related functions (from frontend or built-in MySQL)

From MySQL manual

INET_ATON(expr)

Given the dotted-quad representation of an IPv4 network address as a
string, returns an integer that represents the numeric value of the
address in network byte order (big endian). INET_ATON() returns NULL
if it does not understand its argument.

mysql> SELECT INET_ATON(‘10.0.5.9’);
-> 167773449

For this example, the return value is calculated as 10×2563 + 0×2562 +
5×256 + 9.

INET_ATON() may or may not return a non-NULL result for short-form IP
addresses (such as ‘127.1’ as a representation of ‘127.0.0.1’).
Because of this, INET_ATON()a should not be used for such addresses.

Note:

To store values generated by INET_ATON(), use an INT UNSIGNED column
rather than INT, which is signed. If you use a signed column, values
corresponding to IP addresses for which the first octet is greater
than 127 cannot be stored correctly. See Section 10.6, “Out-of-Range
and Overflow Handling”.

INET_NTOA(expr)

Given a numeric IPv4 network address in network byte order, returns
the dotted-quad representation of the address as a binary string.
INET_NTOA() returns NULL if it does not understand its argument.