void frame(Generator gen) {
super.frame(gen);
if (!gen.hasFrame(m_left) || !gen.hasFrame(m_right)) {
return;
}
QFrame left = gen.getFrame(m_left);
QFrame right = gen.getFrame(m_right);
equate(gen, this, left, right);
}
static Code emit(Generator gen, Expression lexpr, Expression rexpr) {
if (gen.hasFrame(lexpr) && gen.hasFrame(rexpr)) {
QFrame lframe = gen.getFrame(lexpr);
QFrame rframe = gen.getFrame(rexpr);
if (!lframe.isSelect() && !rframe.isSelect()) {
List lvals = lframe.getValues();
List rvals = rframe.getValues();
List lnull = gen.getNull(lexpr);
List rnull = gen.getNull(rexpr);
if (lvals.size() != rvals.size()) {
if (lvals.size() == 1 && lnull.containsAll(lvals)) {
lvals = repeat(lvals.get(0), rvals.size());
} else if (rvals.size() == 1 && rnull.containsAll(rvals)) {
rvals = repeat(rvals.get(0), lvals.size());
} else {
throw new IllegalStateException("signature missmatch: " + lvals + ", " + rvals);
}
}
List conds = new ArrayList();
for (int i = 0; i < lvals.size(); i++) {
QValue l = (QValue) lvals.get(i);
QValue r = (QValue) rvals.get(i);
Code lsql = l.emit();
Code rsql = r.emit();
if (lsql.isNull()) {
if (!r.isNullable()) {
return Code.FALSE;
}
} else if (rsql.isNull()) {
if (!l.isNullable()) {
return Code.FALSE;
}
}
if (!lsql.equals(rsql)) {
conds.add(emit(lsql, null, rsql, null));
}
}
if (conds.isEmpty()) {
return Code.TRUE;
} else {
return Code.join(conds, " and ");
}
}
}
// XXX: we can to do something smarter than this for
// multi column selects
Code lsql = lexpr.emit(gen);
Code rsql = rexpr.emit(gen);
// we need the isEmpty test because we don't want to eliminate
// redundent bind var comparison the first time a query is
// cached since the sql may not be redundent for subsequent
// query executions
if (lsql.getBindings().isEmpty() && lsql.equals(rsql)) {
return Code.TRUE;
} else {
return emit(lsql, lexpr, rsql, rexpr);
}
}