Sort List<> with chars and numbers

Question

I'm working on an Update-Tool for a program my company developed. To update the programm I need to execute some SQL-Scripts. These scripts must have the right order (of course). I have a List. The SqlScriptModel has a 'Name' Property, I used to sort the list. The SQL-Scripts-Name start with the Programm-Version (example: 5.8.1.0). At the moment my 'sorted' list looks like this:

5.8.0.1 - Update Script
5.8.0.10 - Update Script
5.8.0.11 - Update Script
5.8.0.2 - Update Script

Of course the 5.8.0.10 script needs to be executed after the 5.8.0.2 script.

My code looks like this:

SqlScriptList.Sort((x, y) => string.Compare(x.Name, y.Name));

Has somebody already had the same problem? Or has a link to a valid solution? I would be very thankful!

Answer 1

Just rename your files so that all version substrings are of the same length. Pad the last part of the version with zeroes like this:

5.8.0.01 - Update Script
5.8.0.02 - Update Script
5.8.0.10 - Update Script
5.8.0.11 - Update Script

If you don't want to do this, in the code you can convert the version string to a number and then sort based on that number:

string version = "5.8.0.10";
int fullVersionNumber =
    version
        .Split(new char[] { '.' })
        .Select(int.Parse)
        .Aggregate((first, second) => first * 100 + second);
// fullVersionNumber = 5080010

You can make a function out of this:

public static int GetNumericVersion(string fileName)
{
    string version = fileName.Split(new char[] { ' ' })[0];
    int fullVersionNumber =
        version
            .Split(new char[] { '.' })
            .Select(int.Parse)
            .Aggregate((first, second) => first * 100 + second);

    return fullVersionNumber;
}

And use it like this:

SqlScriptList.Sort(
    (x, y) => GetNumericVersion(x.Name).CompareTo(GetNumericVersion(y.Name)));

Answer 2

Consider using Version class from .Net framework, it has a suitable compare operator.

Sample code:

        List<Version> versions = new List<Version>();
        List<string> versionStrings;

        // get somehow, the list of version strings in "Version format" - nothing else except x.y.z.k
        versionStrings = new List<string>(
            new string[]{ "5.8.0.1",
                "5.8.0.10",
                "5.8.0.11",
                "5.8.0.2" }
            );

        // pupulate list of Version from list of string
        versionStrings.ForEach(str => versions.Add(new Version(str)));

        //list is not orderded
        versions.ForEach(ver => System.Diagnostics.Debug.WriteLine(ver));
        // sort the list using the default Version comparison
        versions.Sort();
        // list is ordered
        versions.ForEach(ver => System.Diagnostics.Debug.WriteLine(ver));