added top cities in world and city population by district, will add test files before friday

Author: Adinc02

src/main/java/com/napier/sem/App.java

@@ -114,6 +114,17 @@ public static void main(String[] args)
         ArrayList<City> cityInDistrict = cityReport.printCitiesByDistrict("Oran");
         cityReport.printCities(cityInDistrict);
 
+        // --- Top N Most Populated Cities Globally ---
+        System.out.println("\n=== Top 10 Most Populated Cities in the World ===");
+        ArrayList<City> topWorldCities = cityReport.getTopNCitiesInWorld(10);
+        cityReport.printCities(topWorldCities);
+
+// --- Top N Most Populated Cities in a District ---
+        System.out.println("\n=== Top 5 Most Populated Cities in a District ===");
+        ArrayList<City> CityPopulationDistrict = cityReport.CityPopulationDistrict("California", 5);
+        cityReport.printCities(CityPopulationDistrict);
+
+
 
 
         // Disconnect from database

src/main/java/com/napier/sem/CityReport.java

@@ -62,8 +62,8 @@ public ArrayList<City> printCitiesByContinent(String continent) {
      */
     public ArrayList<City> printCitiesByRegion(String region) {
         String sql = """
-                SELECT city.Name AS CityName, country.Name AS Country,city.District AS District, city.Population AS Population 
-                FROM city JOIN country ON city.CountryCode = country.Code 
+                SELECT city.Name AS CityName, country.Name AS Country,city.District AS District, city.Population AS Population
+                FROM city JOIN country ON city.CountryCode = country.Code
                 WHERE country.Region = ?
                 ORDER BY city.Population DESC
                 """;
@@ -78,14 +78,56 @@ public ArrayList<City> printCitiesByRegion(String region) {
      */
     public ArrayList<City> printCitiesByDistrict(String district) {
         String sql = """
-                SELECT city.Name AS CityName, country.Name AS Country,city.District AS District, city.Population AS Population 
+                SELECT city.Name AS CityName, country.Name AS Country,city.District AS District, city.Population AS Population
                 FROM city JOIN country ON city.CountryCode = country.Code
                 WHERE city.District = ?
                 ORDER BY city.Population DESC
                 """;
         return executeCapitalCityQuery(sql,district);
     }
 
+    /**
+     * Gets most populated cities in a district
+     * @param district the name of the district
+     * @return a list of the most populated cities in that district
+     */
+
+    public ArrayList<City> CityPopulationDistrict(String district, int limit) {
+        String sql = """
+                SELECT city.Name AS CityName,
+                       country.Name AS Country,
+                       city.District AS District,
+                       city.Population AS Population
+                FROM city
+                JOIN country ON city.CountryCode = country.Code
+                WHERE city.District = ?
+                ORDER BY city.Population DESC
+                LIMIT ?
+                """;
+
+        return executeCapitalCityQuery(sql, district, String.valueOf(limit));
+    }
+
+    /**
+     * Retrieves the top N most populated cities in the world.
+     *
+     * @param limit the number of cities to return (top N).
+     * @return A list of the top N cities globally.
+     */
+    public ArrayList<City> getTopNCitiesInWorld(int limit) {
+        String sql = """
+                SELECT city.Name AS CityName,
+                       country.Name AS Country,
+                       city.District AS District,
+                       city.Population AS Population
+                FROM city
+                JOIN country ON city.CountryCode = country.Code
+                ORDER BY city.Population DESC
+                LIMIT ?
+                """;
+
+        return executeCapitalCityQuery(sql, String.valueOf(limit));
+    }
 
     /**
      * Executes SQL queries and maps results to City objects.