MySQL on Windows crashes on connection attempts

Question

I have a windows application that I am making for a friend, but for some reason, when I try to connect, the app crashes. a message box pops up and says "DBTest hastopped working, windows is checking for a solution to the problem..." after 5 seconds, it closes and the app doesn't launch.

However, when I comment out the info from the app, it works again, but only the app launches, and I can't connect anymore??

I checked the connection on MySQL workbench, and it lets me connect to the website's database, and I can connect to the sites DB remotely, but it will not allow me to do so in the application.

Heres the code that im testing, and the app keeps crashing.

I'm at a loss.

    public partial class Form1 : Form
{
    public MySqlConnection connection;
    public Form1()
    {

        InitializeComponent();

        DBInfo db = new DBInfo();

        string server;
        string database;
        string uid;
        string password;

        server = "XXX";
        database = "XXX";
        uid = "XXX";
        password = "XXX";
        string connectionString;
        connectionString = "Server=" + server + ";" + "Database=" + database + ";"
                + "Uid=" + uid + ";" + "Password" + password + ";";

        connection = new MySqlConnection(connectionString);

        try
        {
            connection.Open();
        }
        catch (MySqlException ex)
        {
            switch (ex.Number)
            {
                case 0:
                    MessageBox.Show("Cannot connect to Server. Contact Admin.");
                    break;

                case 1045:
                    MessageBox.Show("Invalid Username/Password, please try again.");
                    break;
            }
        }
    }

UPDATE:

System.ArgumentException: Format of the initialization string does not conform to specification starting at index 54. at System.Data.Common.DBConnectionOptions.GetKeyValuePair(String connectionString, Int32 currentPosition, StringBuilder buffer, Boolean useOdbcRules, String& keyname, String& keyvalue) at System.Data.Common.DbConnectionOptions.ParseInternal(Hashtable parsetable, String connectionString, Boolean buildChain, Hashtable synonyms, Boolean firstkey) at System.Data.Common.DbConnectionOptions..ctor(String connectionString, Hashtable synonyms, Boolean use OdbcRules) at System.Data.Common.DbConnectionStringBuilder.set_ConnectionString(String value) at MySql.Data.MySqlClient.MySqlConnectionStringBuilder..ctor(string connStr) at MySql.Data.MySqlClient.MySqlConnection.set_ConnectionString(String value) at MySql.Data.MySqlClient.MySqlConnection..ctor(String connectionString) at DBtest.Form1..ctor() in C:\Users\AlexMoreno\Dcouments\Visual Studio\2008\Projects\DBtest\Form1.cs:line 38

Changing the code you posted to now uncomment connection.Open(); and add try/catch logic that was not there originally...changes the question quite a bit. ;) — J0e3gan
However, when I comment out the info from the app, it works again, but only the app launches, and I can't connect anymore?? So does this mean the connection.Open(); statement that you originally had commented out in your code, or does it mean other code that you have not shown commented out? It is tough to hit a target that is shifting and unclear. — J0e3gan
sorry, Im just trying things as I go. To answer your second statement, its both the "connection.Open()", and "connection = new MySQLConnection(connectionstring);" if I comment both out, it works again. — Alex Moreno
Booyah! The exception message and stack trace that you added as an update is exactly what we need to see to help. — J0e3gan
I would, but I need +15 on the site before I can start "+1" on comments, sorry :( — Alex Moreno

J0e3gan J0e3gan · Accepted Answer · 2013-05-12T02:08:27

Wrap a try/catch around the statement to open the connection, and get the details of the exception that is likely being thrown and unhandled:

public partial class Form1 : Form
{
    public MySqlConnection connection;
    public Form1()
    {

        InitializeComponent();

        //DBInfo db = new DBInfo(); // would comment this out since you're not using it

        string server;
        string database;
        string uid;
        string password;

        server = "XXX";
        database = "XXX";
        uid = "XXX";
        password = "XXX";
        string connectionString;
        connectionString = "Server=" + server + ";" + "Database=" + database + ";"
                + "Uid=" + uid + ";" + "Password" + password + ";";

        //connection = new MySqlConnection(connectionString); // not here - for troubleshooting at least

        try
        {
            connection = new MySqlConnection(connectionString); // relocated from above for troubleshooting
            connection.Open();
        }
        (Exception ex) // Yes, Exception - until you know more about what is happening.
        {
            MessageBox.Show(ex.ToString());
        }
    }
}

You could output the details of the error another way - e.g. log them, output them to Debug.Console if you are going to debug the app in Visual Studio; take your pick; you just need to reality check that an exception is unhandled and get its details to proceed.

Also, try commenting out DBInfo db = new DBInfo();. You don't seem to be using it anyway.

UPDATE:

You are missing an = in your connection string - right after Password. So...

connectionString = "Server=" + server + ";" + "Database=" + database + ";"
            + "Uid=" + uid + ";" + "Password" + password + ";";

...should be:

connectionString = "Server=" + server + ";" + "Database=" + database + ";"
            + "Uid=" + uid + ";" + "Password=" + password + ";";

MySQL on Windows crashes on connection attempts

1 Answers