void Relation::project(map<int, string>& variables)
{
set<Tuple> newTuples;
Scheme newScheme;
Tuple t;
for (auto& v : variables){
newScheme.addAttribute(scheme.getAttributes().at(v.first));
}
for (auto& tup : tuples){
for (auto& v : variables)
{
t.addAttValue(tup.at(v.first));
}
if (variables.size() > 0){
newTuples.insert(t);
t.clear();
}
}
tuples = newTuples;
scheme = newScheme;
setName("project");
}
void Relation::rename(map<int, string>& variables)
{
Scheme newScheme;
for (auto& v : variables){
newScheme.addAttribute(v.second);
}
scheme = newScheme;
setName("rename");
}