diff --git a/src/main/java/datamodel/Database.java b/src/main/java/datamodel/Database.java
index 6e83b95..bc09d82 100755
--- a/src/main/java/datamodel/Database.java
+++ b/src/main/java/datamodel/Database.java
@@ -204,8 +204,15 @@ public Show getShowData(String movie, String date) {
 
         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);
+
+            if (s.getSeats() <= 0) {
+                System.err.println("addReservation: no free seats for " + movie + " on " + date);
+                return null;
+            }
+
             ResultSet rs = stmt.executeQuery("SELECT * FROM Users WHERE username = '" + username + "'");
             if (rs.next()) {
                 int user_id = rs.getInt("id");
@@ -216,14 +223,23 @@ public Show getShowData(String movie, String date) {
                     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);
                 }
+                rs.close();
             }
             else {
                 System.err.println(String.format("addReservation: user %s not found", username));
             }
+            conn.commit();
         } catch (SQLException e) {
+            try {
+                conn.rollback();
+            } catch (SQLException e2) {
+                e2.printStackTrace();
+            }
             e.printStackTrace();
         }
         return null;