Question

I am currently working on a patching system in C# and I have came across a small complication. I am using MySQL to store an archive for my update list. The patching system then detects the version of program, and downloads every patch after that version. Though I just started learning how to use MySQL in C# so i’m not sure how to do, or call a lot of the functions needed. What I want to do is use foreach to call all values in the “version” column/row, then use a while loop to check against current version and new version until they are the same. I just cant seem to figure out how to use the two together and can’t find any references.

using (SqlCon = new MySqlConnection(connString))
{
    SqlCon.Open();
    string command = "SELECT * FROM version ORDER BY version";
    MySqlCommand GetLatestVersion = new MySqlCommand(command, SqlCon);

    using (MySqlDataReader DR = GetLatestVersion.ExecuteReader())
    {
        while (DR.Read())
        {
            foreach(DataTable i in DR)
            {
                while(v1 < v2)
                {
                    string LatestVersion = Convert.ToString(DR.GetValue(1));
                    string WebURL = Convert.ToString(DR.GetValue(2));
                    update.DownloadProgressChanged += new DownloadProgressChangedEventHandler(download);
                    update.DownloadFileCompleted += new AsyncCompletedEventHandler(extration);
                    update.DownloadFileAsync(new Uri(WebURL), tempFilePath + "patch" + Latest_Version + ".zip");
                }
            }
        }
    }
}
SqlCon.Close();

I would greatly appreciate any help.

Answer 1

First thing is you don’t need the SqlCon.Close(); at the end. At the end of the using block, the object is disposed of (the point of a using block).

You can modify your select statement to only select versions greater than your program’s current version. This way, any records selected should be processed/downloaded. (I put the version in quotes in the SQL statement below because your code indicates that it’s a string. You’re probably better off specifying this value as numeric for sorting/comparison purposes, though.)

//for readability, I changed the variable name to myProgramsVersion

using (SqlCon = new MySqlConnection(connString))
{
    SqlCon.Open();
    string command = "SELECT * FROM version where version > '" + myProgramsVersion + "' ORDER BY version";
    MySqlCommand GetLatestVersion = new MySqlCommand(command, SqlCon);

    using (MySqlDataReader DR = GetLatestVersion.ExecuteReader())
    {
        while (DR.Read())
        {
            string LatestVersion = Convert.ToString(DR.GetValue(1));
            string WebURL = Convert.ToString(DR.GetValue(2));
            update.DownloadProgressChanged += new DownloadProgressChangedEventHandler(download);
            update.DownloadFileCompleted += new AsyncCompletedEventHandler(extration);
            update.DownloadFileAsync(new Uri(WebURL), tempFilePath + "patch" + Latest_Version + ".zip");
        }
    }
}