MySqlConnection myConn = new MySqlConnection("server=127.0.0.1;user id=root;Password=12345;database=test;character set=utf8");
MySqlCommand myComm;
try
{
myConn.Open();
myComm = new MySql.Data.MySqlClient.MySqlCommand();
myComm.Connection = myConn;
myComm.CommandText = "SET @aa=1; SELECT @aa;";
object ret = myComm.ExecuteScalar();
if (ret != null)
{
MessageBox.Show(ret.ToString());
}
}
catch (Exception ex)
{
MessageBox.Show(string.Format("Error: {0}", ex.Message), "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
}
finally
{
myConn.Close();
}

DECLARE @aa int; SET @aa=1;