SQL query to display available seats - Java

Question

I have a table called Rooms and this how the table looks like

 CREATE TABLE Rooms 
 (
     id INT AUTO_INCREMENT,
     RoomNumber VARCHAR(32) NOT NULL,
     AvailableSeats INT NOT NULL,
     PRIMARY KEY (id)   
 ) 

In my code below, i am able to fill the combo box with the room numbers in the database. But what i want to do is, when i select a room number, the available seats for that room number must update.

For instance, when i select

RoomNumber 4, available seats 4

RoomNumber 3, available seats 2

How can i achieve this ?

Query

// query to fetch room numbers to combo box

public void FindRoom() {
    String query = "Select * from Rooms";
    try {
        Statement stmt = conn.createStatement();
        ResultSet rs = stmt.executeQuery(query);
        while(rs.next()) {
            String getRoomNumber = rs.getString("RoomNumber");
            FindRoom.addItem(getRoomNumber);
        }
    } catch (Exception ex) {
        JOptionPane.showMessageDialog(null, ex);
    }
}

//query to get respective available seats for every room number

public void FindSeats() {
    String query = "Select * from Rooms where RoomNumber = "+FindRoom.getSelectedItem();
    try {
        Statement stmt = conn.createStatement();
        ResultSet rs = stmt.executeQuery(query);
        while(rs.next()) {
            String getAvailableSeat = rs.getString("AvailableSeats");
            seats.setText(getAvailableSeat);
        }
    } catch (Exception ex) {
        JOptionPane.showMessageDialog(null, ex);
    }
}