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();
}
public Rndm_rng_itm Exec_rng_end_or_null() {
if (seq_in_rng == 0) return null; // no sequences added; return null;
Rndm_rng_itm rv = new Rndm_rng_itm(qry_idx, rng_idx, rng_seq_bgn, seq_in_qry);
rng_tbl.Insert(rng_stmt, qry_idx, rng_idx, rng_seq_bgn, seq_in_qry);
return rv;
}