@Test
  public void testOneToManyAssosiation() throws Exception {
    MetadataFactory mf = oneToManyRelationMetadata();

    Table g1 = mf.getSchema().getTable("G1");
    Table g2 = mf.getSchema().getTable("G2");

    ForeignKey fk = g2.getForeignKeys().get(0);
    assertEquals("one_2_many", fk.getName());
    assertNotNull(fk.getColumnByName("e1"));
  }
  @Test
  public void testAssosiationWithReferentialContriant() throws Exception {
    ODataMetadataProcessor processor = new ODataMetadataProcessor();
    MetadataFactory mf =
        new MetadataFactory(
            "vdb",
            1,
            "northwind",
            SystemMetadata.getInstance().getRuntimeTypeMap(),
            new Properties(),
            null);

    CsdlEntityType g1Entity = entityType("g1");
    g1Entity.getProperties().add(createProperty("g2e2", EdmPrimitiveTypeKind.String));
    g1Entity.setKey(Arrays.asList(new CsdlPropertyRef().setName("g2e2")));
    CsdlEntityType g2Entity = entityType("g2");

    CsdlNavigationProperty navProperty = new CsdlNavigationProperty();
    navProperty.setName("one_2_one");
    navProperty.setType("namespace.g2");
    navProperty.setNullable(false);
    navProperty.setPartner("PartnerPath");
    navProperty.setReferentialConstraints(
        Arrays.asList(
            new CsdlReferentialConstraint().setProperty("g2e2").setReferencedProperty("e2")));

    g1Entity.setNavigationProperties(Arrays.asList(navProperty));

    CsdlEntitySet g1Set = createES("G1", "namespace.g1");
    CsdlEntitySet g2Set = createES("G2", "namespace.g2");

    CsdlNavigationPropertyBinding navBinding = new CsdlNavigationPropertyBinding();
    navBinding.setPath("one_2_one");
    navBinding.setTarget("G2");
    g1Set.setNavigationPropertyBindings(Arrays.asList(navBinding));

    XMLMetadata metadata = buildXmlMetadata(g1Entity, g1Set, g2Entity, g2Set);
    processor.getMetadata(mf, metadata);

    Table g1 = mf.getSchema().getTable("G1");
    Table g2 = mf.getSchema().getTable("G2");

    assertNotNull(g1);
    assertNotNull(g2);

    ForeignKey fk = g2.getForeignKeys().get(0);
    assertEquals("one_2_one", fk.getName());
    assertNotNull(fk.getColumnByName("e2"));
    assertEquals("g2e2", fk.getReferenceColumns().get(0));
  }
  private static void buildAssosiationSets(MetadataStore metadataStore, List<Builder> edmSchemas) {
    for (Schema schema : metadataStore.getSchemaList()) {

      EdmSchema.Builder odataSchema = findSchema(edmSchemas, schema.getName());
      EdmEntityContainer.Builder entityContainer =
          findEntityContainer(edmSchemas, schema.getName());
      List<EdmAssociationSet.Builder> assosiationSets = new ArrayList<EdmAssociationSet.Builder>();
      List<EdmAssociation.Builder> assosiations = new ArrayList<EdmAssociation.Builder>();

      for (Table table : schema.getTables().values()) {
        // build Associations
        for (ForeignKey fk : table.getForeignKeys()) {

          EdmEntitySet.Builder entitySet =
              findEntitySet(edmSchemas, schema.getName(), table.getName());
          EdmEntitySet.Builder refEntitySet =
              findEntitySet(edmSchemas, schema.getName(), fk.getReferenceTableName());
          EdmEntityType.Builder entityType =
              findEntityType(edmSchemas, schema.getName(), table.getName());
          EdmEntityType.Builder refEntityType =
              findEntityType(edmSchemas, schema.getName(), fk.getReferenceTableName());

          // check to see if fk is part of this table's pk, then it is 1 to 1 relation
          boolean onetoone = sameColumnSet(table.getPrimaryKey(), fk);

          // Build Association Ends
          EdmAssociationEnd.Builder endSelf =
              EdmAssociationEnd.newBuilder()
                  .setRole(table.getName())
                  .setType(entityType)
                  .setMultiplicity(onetoone ? EdmMultiplicity.ZERO_TO_ONE : EdmMultiplicity.MANY);

          EdmAssociationEnd.Builder endRef =
              EdmAssociationEnd.newBuilder()
                  .setRole(fk.getReferenceTableName())
                  .setType(refEntityType)
                  .setMultiplicity(EdmMultiplicity.ZERO_TO_ONE);

          // Build Association
          EdmAssociation.Builder association = EdmAssociation.newBuilder();
          association.setName(table.getName() + "_" + fk.getName());
          association.setEnds(endSelf, endRef);
          association.setNamespace(
              refEntityType
                  .getFullyQualifiedTypeName()
                  .substring(0, refEntityType.getFullyQualifiedTypeName().indexOf('.')));
          assosiations.add(association);

          // Build ReferentialConstraint
          if (fk.getReferenceColumns() != null) {
            EdmReferentialConstraint.Builder erc = EdmReferentialConstraint.newBuilder();
            erc.setPrincipalRole(fk.getReferenceTableName());
            erc.addPrincipalReferences(fk.getReferenceColumns());
            erc.setDependentRole(table.getName());
            erc.addDependentReferences(getColumnNames(fk.getColumns()));
            association.setRefConstraint(erc);
          }

          // Add EdmNavigationProperty to entity type
          EdmNavigationProperty.Builder nav =
              EdmNavigationProperty.newBuilder(fk.getReferenceTableName());
          nav.setRelationshipName(fk.getName());
          nav.setFromToName(table.getName(), fk.getReferenceTableName());
          nav.setRelationship(association);
          nav.setFromTo(endSelf, endRef);
          entityType.addNavigationProperties(nav);

          // Add EdmNavigationProperty to Reference entity type
          EdmNavigationProperty.Builder refNav = EdmNavigationProperty.newBuilder(table.getName());
          refNav.setRelationshipName(fk.getName());
          refNav.setFromToName(fk.getReferenceTableName(), table.getName());
          refNav.setRelationship(association);
          refNav.setFromTo(endRef, endSelf);
          refEntityType.addNavigationProperties(refNav);

          // build AssosiationSet
          EdmAssociationSet.Builder assosiationSet =
              EdmAssociationSet.newBuilder()
                  .setName(table.getName() + "_" + fk.getName())
                  .setAssociationName(fk.getName());

          // Build AssosiationSet Ends
          EdmAssociationSetEnd.Builder endOne =
              EdmAssociationSetEnd.newBuilder()
                  .setEntitySet(entitySet)
                  .setRoleName(table.getName())
                  .setRole(
                      EdmAssociationEnd.newBuilder()
                          .setType(entityType)
                          .setRole(entityType.getName()));

          EdmAssociationSetEnd.Builder endTwo =
              EdmAssociationSetEnd.newBuilder()
                  .setEntitySet(refEntitySet)
                  .setRoleName(fk.getReferenceTableName())
                  .setRole(
                      EdmAssociationEnd.newBuilder()
                          .setType(refEntityType)
                          .setRole(refEntityType.getName()));
          assosiationSet.setEnds(endOne, endTwo);

          assosiationSet.setAssociation(association);
          assosiationSets.add(assosiationSet);
        }
      }
      entityContainer.addAssociationSets(assosiationSets);
      odataSchema.addAssociations(assosiations);
    }
  }