Question

I have this code that I use for copy one table to another, but I got error while executing command statement.

Error says that connection is not open or valid. When I debug I can see it is opened.
Really don’t know why is not valid.

con.ConnectionString = ConfigurationManager.ConnectionStrings["Con2"].ConnectionString;
con.Open();
cmd = new MySqlCommand("SELECT COUNT(*) FROM " + ConfigSettings.ReadSetting("main_base"), con);
int nRows = Convert.ToInt32(cmd.ExecuteScalar());
con.Close();
if (nRows > 0)
{
    con.ConnectionString = ConfigurationManager.ConnectionStrings["Con1"].ConnectionString;
    con.Open();
    cmd = new MySqlCommand("INSERT INTO temp_data SELECT * FROM data");
    cmd.ExecuteScalar();
}

Everything goes well until last command:

cmd = new MySqlCommand("INSERT INTO temp_data SELECT * FROM data");
cmd.ExecuteScalar();

Is this even possible if these two database are on different servers? Maybe I need to have two connections opened at the same time or something like that?

Answer 1

Pass the connection object to the MySqlCommand constructor:

cmd = new MySqlCommand("INSERT INTO temp_data SELECT * FROM data", con);