Bug #40765 Connector net 5.2.4 Fatal error encountered during command execution

Description:
ExecuteReader() method of the MySqlCommand object displays "Fatal error encountered during command execution" message when the simple statement below is executed.

select @data := 3, @data * 4;

How to repeat:
MySqlConnection con = new MySqlConnection();
con.ConnectionString = "Database=sampledb;Data Source=localhost;User Id=root;Password=a";
con.Open();
// Connection ok
string cmdText = "select @data := 3, @data * 4;";
MySqlCommand cmd = new MySqlCommand(cmdText, con);
MySqlDataReader r = cmd.ExecuteReader();
r.Read();
MessageBox.Show(r.GetInt32(1).ToString());
r.Close();
con.Close();
r.Dispose();
con.Dispose();

Neoh

This is not a bug.  You are attempting to use user variables in your sql.  The default mode for Connector/Net assumes you will not be using user variables (as most users don't) and so it sees @data and expects to find a parameter named @data.  When it doesn't find one it throws an exception.

To fix this add 'allow user variables=true' to your connection string.  In this mode it will not complain when it sees @data but doesn't find a parameter of that name.

Well thanks a lot. I really thought It was a bug. I usually include user variables in some of my queries and get no problem with connector/net 5.1.4. I never thought this feature will be disabled by default in higher versions. Thanks for the info, this really helped a lot.

thanks mr. Reggie Burnett

It really a big help guys...

Could anyone tell me how to make that user variable set to true?

Dim conn
        conn = New MySqlConnection()
        myConnString = "server=" & TextBox1.Text & ";" _
    & "user id=" & TextBox3.Text & ";" _
    & "password=" & TextBox2.Text & ";" _
    & "database=" & TextBox4.Text

        conn.ConnectionString = myConnString

Dos it go somewhere here?

Could anyone tell me how to make that user variable set to true?

Dim conn
        conn = New MySqlConnection()
        myConnString = "server=" & TextBox1.Text & ";" _
    & "user id=" & TextBox3.Text & ";" _
    & "password=" & TextBox2.Text & ";" _
    & "database=" & TextBox4.Text

        conn.ConnectionString = myConnString

Dos it go somewhere here?

Dim conn
        conn = New MySqlConnection()
        myConnString = "Data Source=" & TextBox1.Text & ";" _
    & "User Id=" & TextBox3.Text & ";" _
    & "Password=" & TextBox2.Text & ";" _
    & "Database=" & TextBox4.Text & ";" _
    & "Allow User Variables=True"

        conn.ConnectionString = myConnString