Question

Is there an other way to insert multiple objects to an MySQL database than the way shown here. This works but takes time to execute.

  using (MySql.Data.MySqlClient.MySqlConnection conn = new MySql.Data.MySqlClient.MySqlConnection(connStr))
        {
            //Goes thrue the List<object>
            foreach(List<object> sub in listSubject)
            {
            MySql.Data.MySqlClient.MySqlCommand cmd = new MySql.Data.MySqlClient.MySqlCommand();
            cmd.Connection = conn;
            cmd.CommandText = "CALL stp_InsertSubject(@param_SubjectId, @param_ProjectId, @param_Used);";
            cmd.Parameters.AddWithValue("@param_SubjectId",Convert.ToInt32(sub[0]) );
            cmd.Parameters.AddWithValue("@param_ProjectId", Convert.ToInt32(sub[1]));
            cmd.Parameters.AddWithValue("@param_Used", Convert.ToBoolean(sub[2]) );

            conn.Open();

            cmd.ExecuteNonQuery();

            conn.Close();
                }

My Stored procedure:

CREATE DEFINER=`mortenstarck`@`%` PROCEDURE `stp_InsertSubject`(param_SubjectId int(45), param_ProjectId int(45), param_Used tinyint(1))

BEGIN
INSERT INTO Subject_has_Projects(Subject_Id, Projects_Id, Used) VALUES (param_SubjectId, param_ProjectId, param_Used);
END

Answer 1

Few things to improve:

• Open the connection just one time outside the loop (no need to close
  with using)
• Create the command, assign connection just one time before the loop
• Create the parameters all before the loop with dummy values
• Assign only the value inside the loop and call the ExecuteScalar()

using(MySql.Data.MySqlClient.MySqlConnection conn = new MySql.Data.MySqlClient.MySqlConnection(connStr))
{
conn.Open();
MySql.Data.MySqlClient.MySqlCommand cmd = new MySql.Data.MySqlClient.MySqlCommand();
cmd.Connection = conn;
cmd.CommandText = "CALL stp_InsertSubject(@param_SubjectId, @param_ProjectId, @param_Used);";
cmd.Parameters.AddWithValue("@param_SubjectId",0 );
cmd.Parameters.AddWithValue("@param_ProjectId", 0);
cmd.Parameters.AddWithValue("@param_Used", false );
foreach(List<object> sub in listSubject)
{
cmd.Parameters["@param_SubjectId"].Value = Convert.ToInt32(sub[0]) ;
cmd.Parameters["@param_ProjectId"].Value = Convert.ToInt32(sub[1]);
cmd.Parameters["@param_Used"].Value = Convert.ToBoolean(sub[2]);
Id = (Int64)cmd.ExecuteScalar();
}
}