diff --git a/src/main/java/datamodel/Database.java b/src/main/java/datamodel/Database.java
index bc09d82..4524220 100755
--- a/src/main/java/datamodel/Database.java
+++ b/src/main/java/datamodel/Database.java
@@ -197,14 +197,14 @@ public Show getShowData(String movie, String date) {
     }
 
     public Reservation addReservation(String username, String movie, String date) {
-        if(!isConnected()) {
+        if (!isConnected()) {
             System.err.println("addReservation: no connection to database");
             return null;
         }
 
         System.out.println("Adding reservation for " + username + " for " + movie + " on " + date);
 
-        try(Statement stmt = conn.createStatement()) {
+        try (Statement stmt = conn.createStatement()) {
             conn.setAutoCommit(false);
             Show s = getShowData(movie, date);
 
@@ -213,27 +213,46 @@ public Show getShowData(String movie, String date) {
                 return null;
             }
 
-            ResultSet rs = stmt.executeQuery("SELECT * FROM Users WHERE username = '" + username + "'");
-            if (rs.next()) {
-                int user_id = rs.getInt("id");
-                rs = stmt.executeQuery("SELECT * FROM Showings JOIN Movies ON Showings.movie_id = Movies.movie_id WHERE name = '" + movie + "' AND show_date = '" + date + "'");
-                if (rs.next()) {
-                    System.out.println("Adding reservation");
-                    int showing_id = rs.getInt("showing_id");
-                    String theater = rs.getString("theater_id");
-                    stmt.executeUpdate("INSERT INTO Reservations (user_id, showing_id) VALUES (" + user_id + ", " + showing_id + ")");
-                    System.out.println("Reservation added");
-                    conn.commit();
-                    conn.setAutoCommit(true);
-                    int bookingId = stmt.getGeneratedKeys().getInt(1);
-                    return new Reservation(bookingId, movie, date, theater);
+            try (PreparedStatement userQuery = conn.prepareStatement("SELECT * FROM Users WHERE username = ?");
+                PreparedStatement showingQuery = conn.prepareStatement("SELECT * FROM Showings JOIN Movies ON Showings.movie_id = Movies.movie_id WHERE name = ? AND show_date = ?");
+                PreparedStatement reservationInsert = conn.prepareStatement("INSERT INTO Reservations (user_id, showing_id) VALUES (?, ?)", Statement.RETURN_GENERATED_KEYS)) {
+
+                userQuery.setString(1, username);
+                try (ResultSet rs = userQuery.executeQuery()) {
+                    if (rs.next()) {
+                        int user_id = rs.getInt("id");
+
+                        showingQuery.setString(1, movie);
+                        showingQuery.setString(2, date);
+                        try (ResultSet showingRs = showingQuery.executeQuery()) {
+                            if (showingRs.next()) {
+                                // Getting the data from the showing query
+                                int showing_id = showingRs.getInt("showing_id");
+                                String theater = showingRs.getString("theater_id");
+
+                                // Preparing the reservation insert with the data previously retrieved
+                                reservationInsert.setInt(1, user_id);
+                                reservationInsert.setInt(2, showing_id);
+                                reservationInsert.executeUpdate();
+
+                                // Committing the transaction and getting the generated keys
+                                conn.commit();
+                                conn.setAutoCommit(true);
+                                
+                                // Getting the generated keys, if any
+                                try (ResultSet generatedKeys = reservationInsert.getGeneratedKeys()) {
+                                    if (generatedKeys.next()) {
+                                        int bookingId = generatedKeys.getInt(1);
+                                        return new Reservation(bookingId, movie, date, theater);
+                                    }
+                                }
+                            }
+                        }
+                    } else {
+                        System.err.println(String.format("addReservation: user %s not found", username));
+                    }
                 }
-                rs.close();
             }
-            else {
-                System.err.println(String.format("addReservation: user %s not found", username));
-            }
-            conn.commit();
         } catch (SQLException e) {
             try {
                 conn.rollback();
@@ -245,6 +264,7 @@ public Show getShowData(String movie, String date) {
         return null;
     }
 
+
     public ArrayList<Reservation> getReservations(String username) {
         ArrayList<Reservation> reservations = new ArrayList<Reservation>();