有没有办法让 JButton 在第一次按下时做一件事，第二次按下时做其他事

Question

I am using prepared statements in Java to insert monthly finances into a database table. The first time I press the button each month I want it to SQL query insert, but the other times just update in order to avoid repeats for the same month. How would I be able to do this?

This is my code

    String dbQuery18 = "INSERT INTO weekly_finances VALUES (?,?,?,?)";
    String dbQuery19 = "INSERT INTO monthly_finances VALUES (?,?,?,?)";
    // Data to be entered 
    int weekNumber = 0;
    int monthNumber = 0;
    float weeklySum = 0;
    float monthlySum = 0;

    if (command.equals("Save"))
    {
        try
        {
            try
            {
                day = thisDay;
                weekNumber = thisWeek;
                monthNumber = thisMonth;

                PreparedStatement ps16 = myDbConn.prepareStatement(dbQuery16);
                // Passing Values into ps to fill in
                ps16.setInt(1, weekNumber);
                ResultSet res = ps16.executeQuery();
                while (res.next())
                {
                    int c = res.getInt(1);
                    weeklySum = weeklySum + c;
                };

                System.out.println("This is the weekly Sum = " + weeklySum);

                PreparedStatement ps17 = myDbConn.prepareStatement(dbQuery17);
                // Passing Values into ps to fill in
                ps17.setInt(1, monthNumber);
                ResultSet res1 = ps17.executeQuery();
                while (res1.next())
                {
                    int d = res1.getInt(1);
                    monthlySum = monthlySum + d;
                };

                // Inputting into Database 
                // Prepare Statement using Connection 
                PreparedStatement ps18 = myDbConn.prepareStatement(dbQuery18);
                // Passing Values into ps to fill in
                ps18.setInt(1, weekNumber);
                ps18.setFloat(2, weeklySum);
                ps18.setFloat(3, NULL);
                ps18.setFloat(4, NULL);         
                // Executing Update
                ps18.executeUpdate();

                PreparedStatement ps19 = myDbConn.prepareStatement(dbQuery19);
                // Passing Values into ps to fill in
                ps19.setInt(1, monthNumber);
                ps19.setFloat(2, monthlySum);
                ps19.setFloat(3, NULL);
                ps19.setFloat(4, NULL);  
                // Executing Update
                ps19.executeUpdate();

Answer 1

In case you want multiple buttons to have that effect, I would make a ArrayList named "pressedButtons". Then when you handle a click, check if the ArrayList contains the button. If not, there is your first click, and add the user to the ArrayList. If so, that's your second click.

However, in your case when working with sql I just would check if the data already exists via a SQL command, and then act.