@Override
public RelationSchema getClone() {
RelationSchema clone;
ArrayList<Attribute> clonesAttributes = new ArrayList<>();
ArrayList<FunctionalDependency> clonesFunctionalDependencies = new ArrayList<>();
for (Attribute attribute : attributes) {
clonesAttributes.add((Attribute) attribute.getClone());
}
for (FunctionalDependency dependency : functionalDependencies) {
clonesFunctionalDependencies.add(dependency.getClone());
}
clone = new RelationSchema(name, clonesAttributes, clonesFunctionalDependencies);
clone.setOwnId(ownId);
clone.restoreReferences();
clone.initPropertyChangeListeners();
clone.setDirty(super.isDirty());
return clone;
}
/**
* Walks through all Fd's an united the fd's with the same left side
*
* @param relation the RelationSchema as source for the Fd's
*/
private void uniteFdsWithSameLeftSide(RelationSchema relation) {
ArrayList<FunctionalDependency> compactedFds = new ArrayList<>();
for (FunctionalDependency fd : relation.getFunctionalDependencies()) {
if (!containsLeftSide(compactedFds, fd)) {
compactedFds.add(fd);
} else {
uniteWithExistingLeftSide(compactedFds, fd);
}
}
relation.setFunctionalDependencies(compactedFds);
}
@Override
public boolean equals(Object object) {
if (object instanceof RelationSchema) {
RelationSchema otherSchema = (RelationSchema) object;
if (!name.equals(otherSchema.getName())) {
return false;
}
if (!attributes.equals(otherSchema.getAttributes())) {
return false;
}
if (!functionalDependencies.equals(otherSchema.getFunctionalDependencies())) {
return false;
}
}
return true;
}
public NormalizationResult normalize(
RelationSchema relationToNormalize, NormalForm actualNF, NormalForm targetNF) {
RelationSchema relation = relationToNormalize.getClone();
RelationSchema backupRelation;
NormalizationResult result;
// Pick up lonely Attributes (in no Functional dependency)
RelationUtils.getInstance().determineAllAttributes(relation);
// Set primary-key if not present
if (RelationUtils.getInstance().getPrimaryKey(relation).getAttributes().isEmpty()) {
Key newPrimaryKey = RelationUtils.getInstance().getKey(relation);
for (Attribute attribute : relation.getAttributes()) {
if (newPrimaryKey.getAttributes().contains(attribute)) {
attribute.setIsPrimaryKey(true);
}
}
}
backupRelation = relation.getClone();
normalizationProcedures.clear();
switch (actualNF) {
case FIRST:
switch (targetNF) {
case SECOND:
// 1.NF ==> 2.NF
normalizationProcedures.add(new DecompositionTo2NF());
break;
case THIRD:
// 1.NF ==> 3.NF
normalizationProcedures.add(new SyntheseTo3NF());
break;
case BOYCECODD:
// 1.NF ==> BCNF
normalizationProcedures.add(new SyntheseTo3NF());
normalizationProcedures.add(new DecompositionToBCNF());
break;
default:
throw new IllegalArgumentException();
}
break;
case SECOND:
switch (targetNF) {
case THIRD:
// 2.NF ==> 3.NF
normalizationProcedures.add(new SyntheseTo3NF());
break;
case BOYCECODD:
// 2.NF ==> BCNF
normalizationProcedures.add(new SyntheseTo3NF());
normalizationProcedures.add(new DecompositionToBCNF());
break;
default:
throw new IllegalArgumentException();
}
break;
case THIRD:
// 3.NF ==> BCNF
normalizationProcedures.add(new DecompositionToBCNF());
break;
default:
throw new IllegalArgumentException();
}
result = startNormalizing(relation, normalizationProcedures, targetNF);
if (result.getRelations().isEmpty()) {
result.getRelations().add(backupRelation);
}
return result;
}
