jdbc DELETE更新无法在Java代码中运行。

Question

I am working on a small Java JFrame desktop application for my website's staff to be able to delete all reported posts with just one click.

So far, the GUI is correct, with 2 buttons- a getReports button to give the amount of posts, and a deleteReports button.

The getReports function is working properly. However, for whatever reason, the DELETE query is not working. Interestingly enough, when I manually use the query on the database, it deletes the rows in question, so I don't think it is a problem with the query.

Here are, in order, the getReports and deleteReports methods:

public static int getReports() throws InstantiationException, IllegalAccessException {

    Connection conn = null;
        try {

            conn = DriverManager.getConnection(url, username, password);

            Statement stmt = conn.createStatement();
            String sql = "SELECT count(*) as amount FROM `tryreports`";
            ResultSet rs = stmt.executeQuery(sql);
            rs.first();
            int quantity = rs.getInt("amount");
            conn.close();
            return quantity;



        }
        catch (SQLException ex) {
        // handle any errors
        System.out.println("SQLException: " + ex.getMessage());
        System.out.println("SQLState: " + ex.getSQLState());
        System.out.println("VendorError: " + ex.getErrorCode());
        return 0;
        } 



}

public static void deleteReports() throws InstantiationException, IllegalAccessException {

    Connection conn = null;
        try {                
            conn = DriverManager.getConnection(url, username, password);
            //System.out.println("Connected database successfully...");

            Statement stmt = conn.createStatement();
            String sql = "DELETE FROM `tryreports` WHERE posts IS NOT NULL";
            stmt.executeUpdate(sql);



        }
        catch (SQLException ex) {
        // handle any errors
        System.out.println("SQLException: " + ex.getMessage());
        System.out.println("SQLState: " + ex.getSQLState());
        System.out.println("VendorError: " + ex.getErrorCode());
        //return 0;
        } 



}

thoughts? any help would be appreciated.

Answer 1

This was a simple and unbeleivable mistake on my part.

The app has 2 buttons, getReports and deleteReports. I forgot to call the deleteReports() method in the listener method for the delete button.