public void Exec_qry_bgn(Rndm_qry_itm qry_itm) { this.qry_itm = qry_itm; qry_idx = qry_tbl.Select_by_key(qry_itm.Qry_key()); if (qry_idx == -1) qry_idx = ++qry_idx_max; else { // delete all qry_tbl.Delete_by_qry_idx(qry_idx); rng_tbl.Delete_by_qry_idx(qry_idx); seq_tbl.Delete_by_qry_idx(qry_idx); } rng_idx = seq_in_rng = seq_in_qry = 0; rng_stmt = rng_tbl.Insert_stmt(); seq_stmt = seq_tbl.Insert_stmt(); }