join path translation for multiple tables

src/main/java/model/SQLQuery.java

@@ -17,7 +17,7 @@ public class SQLQuery {
 		map = new HashMap<>();
 		map.put("SELECT", new ArrayList<String>());
 		map.put("FROM", new HashSet<String>());
-		map.put("WHERE", new ArrayList<String>());
+		map.put("WHERE", new HashSet<String>());
 	}
 
 	@Deprecated

src/main/java/model/SQLTranslator.java

@@ -12,10 +12,8 @@
 public class SQLTranslator {
 	private SQLQuery query;
 	private SchemaGraph schema;
-	private Node root;
 
 	public SQLTranslator(Node root, SchemaGraph schema) {
-		this.root = root;
 		this.schema = schema;
 		query = new SQLQuery();
 
@@ -108,15 +106,28 @@ private void translateSClause(Node node) {
 		translateGNP(node.getChildren().get(0));
 	}
 
-	private void addJoinPath() {
-		List<String> fromTables = new ArrayList<String>(query.getCollection("FROM"));
-		if (fromTables.size() <= 1) { return; }
-		String table1 = fromTables.get(0);
-		String table2 = fromTables.get(1);
+	private void addJoinKeys(String table1, String table2) {
 		Set<String> joinKeys = schema.getJoinKeys(table1, table2);
 		for (String joinKey : joinKeys) {
 			query.add("WHERE", table1+"."+joinKey+" = "+table2+"."+joinKey);
 		}
 	}
+
+	private void addJoinPath(List<String> joinPath) {
+		for (int i = 0; i < joinPath.size()-1; i++) {
+			addJoinKeys(joinPath.get(i), joinPath.get(i+1));
+		}
+	}
+
+	private void addJoinPath() {
+		List<String> fromTables = new ArrayList<String>(query.getCollection("FROM"));
+		if (fromTables.size() <= 1) { return; }
+		for (int i = 0; i < fromTables.size()-1; i++) {
+			for (int j = i+1; j < fromTables.size(); j++) {
+				List<String> joinPath = schema.getJoinPath(fromTables.get(i), fromTables.get(j));
+				addJoinPath(joinPath);
+			}
+		}
+	}
 
 }

src/main/java/ui/UserView.java

@@ -18,7 +18,8 @@
 import model.NodeInfo;
 
 public class UserView extends Application {
-	private static final String TEST_TEXT = "Return number of authors who published theory papers before 1980.";
+	private static final String TEST_TEXT = "Return the number of authors who published both journal and conference papers after 2000.";
+	// "Return number of authors who published theory papers before 1980."
 
 	Stage stage; // the window
 	Scene scene; // the main content in the window