import java.util.*;

/* this class checks whether a particular attribute belongs to the given relation */
public class RelationLookup
{

/* this HashTable consists of String and a Set */
public Hashtable lookuptable;

public boolean lookup(String relation, Object attribute)
{
HashSet hs = (HashSet)lookuptable.get(relation);
return ( hs.contains(attribute) ) ;
}


/* the Hashtable lookuptable consists of a String(key) and HashSet(value)
   the relation is the key and the attribute set is the HastSet

   CURRENTLY WE ARE HARD-CODING THE RELATION NAMES AND ITS ATTRIBUTES.
   IN FUTURE WE SHOULD GET THIS DATA FROM THE METADATA OBJECT OF THE TABLE FROM THE ORACLE DATABASE
*/


/* ISSUES:  CAPITAL LETTERS, AND STATIC CLASS */
public RelationLookup()
{

lookuptable = new Hashtable();

HashSet hs;

hs = new HashSet();
// adding table location "L"
hs.add(new String("NAME"));
hs.add(new String("X"));
hs.add(new String("Y"));
lookuptable.put(new String("L"), hs);

hs = new HashSet();
//adding table demography "D"
hs.add(new String("NAME"));
hs.add(new String("AGE"));
hs.add(new String("SEX"));
lookuptable.put(new String("D"), hs);

}


}