Connection must be valid and open mysql

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I am having a problem in retirieving the last value in a column in mysql db.
I am getting connection must be valid and open error.
Can someone please help?
Thanks

What I have tried:

String connString = System.Configuration.ConfigurationManager.ConnectionStrings["web"].ToString();
        using (MySqlConnection con = new MySqlConnection(connString))
        {
            using (MySqlCommand cmd = new MySqlCommand("SELECT TOP 1 idProyecto FROM proyectos order by idProyecto DESC LIMIT 1"))
            {
                cmd.CommandType = CommandType.Text;
                cmd.Connection = conn;
                con.Open();
                val1 = cmd.ExecuteScalar().ToString();
                con.Close();
                return val1;

            }
        }

Posted 25-Jan-18 4:59am

Member 10850253

Updated 25-Jan-18 7:56am

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A_Griffin 25-Jan-18 13:52pm

MySQL doesn't use the TOP function - remove that and just use the LIMIT 1 instead. However, from the error message I suspect that your connection string is invalid.

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Dave Kreskowiak · Answer 1 · 2018-01-25T07:54:00

Quote:
cmd.Connection = conn;

You've declared your connection object as "con" and then told your command object to use a connection object called "conn".

Since this actually compiled, it appears you've got another connection object called "conn" somewhere above this in the same scope or in a higher level scope. That would be bad practice to have that.