private Stream<Map.Entry<RelationPredicate, ImmutableList<Integer>>> extractUniqueConstraintsFromRelation( DatabaseRelationDefinition relation) { return relation.getUniqueConstraints().stream() .map(uc -> uc.getAttributes().stream() .map(Attribute::getIndex) .collect(ImmutableCollectors.toList())) .map(positions -> new AbstractMap.SimpleEntry<>(relation.getAtomPredicate(), positions)); }
private LinearInclusionDependency getLinearInclusionDependency(ForeignKeyConstraint fk) { DatabaseRelationDefinition def = fk.getRelation(); DatabaseRelationDefinition def2 = fk.getReferencedRelation(); // create variables for the current table int len1 = def.getAttributes().size(); List<Term> terms1 = new ArrayList<>(len1); for (int i = 1; i <= len1; i++) terms1.add(termFactory.getVariable("t" + i)); // create variables for the referenced table int len2 = def2.getAttributes().size(); List<Term> terms2 = new ArrayList<>(len2); for (int i = 1; i <= len2; i++) terms2.add(termFactory.getVariable("p" + i)); for (ForeignKeyConstraint.Component comp : fk.getComponents()) { // indexes start at 1 int pos1 = comp.getAttribute().getIndex() - 1; // current column (1) int pos2 = comp.getReference().getIndex() - 1; // referenced column (2) terms1.set(pos1, terms2.get(pos2)); } Function head = termFactory.getFunction(def2.getAtomPredicate(), terms2); Function body = termFactory.getFunction(def.getAtomPredicate(), terms1); return new LinearInclusionDependency(head, body); }
}); Function atom = termFactory.getFunction(relation.getAtomPredicate(), terms);