public override string Execute()
        {
            string sMsg = string.Empty;

            SetError(sMsg);
            ResetAffectedRows();
            SQLNoneQuery   sql         = base.ExecutionCommand;
            ConnectionItem connect     = Connection;
            DbTransaction  transaction = Transaction;

            if (sql != null && connect != null)
            {
                DbCommand cmd = connect.ConnectionObject.CreateCommand();
                if (transaction != null)
                {
                    cmd.Transaction = transaction;
                }
                bool bClosed = !connect.ConnectionObject.Opened;
                if (bClosed)
                {
                    connect.ConnectionObject.Open();
                }
                if (connect.ConnectionObject.Opened)
                {
                    try
                    {
                        int i;
                        EnumParameterStyle pstyle = connect.ParameterStyle;
                        cmd.CommandText = sql.SQL;
                        if (sql.CommandType == enmNonQueryType.StoredProcedure)
                        {
                            cmd.CommandType = CommandType.StoredProcedure;
                        }
                        else
                        {
                            cmd.CommandType = CommandType.Text;
                        }
                        int nCount = ParameterCount;
                        for (i = 0; i < nCount; i++)
                        {
                            DbParameter pam = cmd.CreateParameter();
                            if (pstyle == EnumParameterStyle.LeadingQuestionMark)
                            {
                                if (sql.Param_Name[i].StartsWith("@", StringComparison.OrdinalIgnoreCase))
                                {
                                    pam.ParameterName = string.Format(CultureInfo.InvariantCulture, "?{0}", sql.Param_Name[i].Substring(1));
                                }
                                else if (sql.Param_Name[i].StartsWith("?", StringComparison.OrdinalIgnoreCase))
                                {
                                    pam.ParameterName = sql.Param_Name[i];
                                }
                                else
                                {
                                    pam.ParameterName = string.Format(CultureInfo.InvariantCulture, "?{0}", sql.Param_Name[i]);
                                }
                            }
                            else
                            {
                                if (sql.Param_Name[i].StartsWith("@", StringComparison.OrdinalIgnoreCase))
                                {
                                    pam.ParameterName = sql.Param_Name[i];
                                }
                                else
                                {
                                    pam.ParameterName = string.Format(CultureInfo.InvariantCulture, "@{0}", sql.Param_Name[i]);
                                }
                            }
                            pam.DbType    = ValueConvertor.OleDbTypeToDbType(sql.Param_OleDbType[i]);
                            pam.Direction = this.Param_Directions[i];
                            pam.Size      = EPField.FieldDataSize(sql.Param_OleDbType[i], this.Param_DataSize[i]);
                            pam.Value     = ValueConvertor.ConvertByOleDbType(sql.Parameters[i].Value, sql.Param_OleDbType[i]);
                            cmd.Parameters.Add(pam);
                        }
                        cmd.Prepare();
                        DbDataReader dr = cmd.ExecuteReader();

                        _dataset = new DataSet("Results");
                        int n = 1;
                        while (true)
                        {
                            DataTable tbl = new DataTable(string.Format("Table{0}", n));
                            for (i = 0; i < dr.FieldCount; i++)
                            {
                                DataColumn dc = new DataColumn(dr.GetName(i), dr.GetFieldType(i));
                                tbl.Columns.Add(dc);
                            }
                            _dataset.Tables.Add(tbl);
                            while (dr.Read())
                            {
                                object[] vs = new object[dr.FieldCount];
                                for (int k = 0; k < dr.FieldCount; k++)
                                {
                                    vs[k] = dr.GetValue(k);
                                }
                                tbl.Rows.Add(vs);
                            }
                            n++;
                            if (!dr.NextResult())
                            {
                                break;
                            }
                        }
                        dr.Close();
                        if (bClosed)
                        {
                            closeConnections();
                        }
                        for (i = 0; i < nCount; i++)
                        {
                            ParameterDirection pt = cmd.Parameters[i].Direction;
                            if (pt != ParameterDirection.Input)
                            {
                                sql.Parameters[i].Value = cmd.Parameters[i].Value;
                            }
                        }
                        FireExecuteFinish();
                    }
                    catch (Exception er)
                    {
                        if (transaction != null)
                        {
                            transaction.Rollback();
                            transaction.Dispose();
                            ResetTransaction();
                            throw;
                        }
                        else
                        {
                            sMsg = ExceptionLimnorDatabase.FormExceptionText(er);
                        }
                    }
                    finally
                    {
                        if (bClosed)
                        {
                            if (connect.ConnectionObject.State != ConnectionState.Closed)
                            {
                                connect.ConnectionObject.Close();
                            }
                        }
                    }
                }
                else
                {
                    sMsg = "Database connection not set";
                }
            }
            else
            {
                sMsg = "SQL statement not set";
            }
            if (!string.IsNullOrEmpty(sMsg))
            {
                SetError(sMsg);
            }
            return(sMsg);
        }