Java : JDBC Delete Row Issue

Question

这是GUI程序，当单击按钮时它会删除该行。但问题是它给出这样的异常

Cannot delete or update a parent row: a foreign key constraint fails (`sakila`.`film_actor`, CONSTRAINT `fk_film_actor_actor` FOREIGN KEY (`actor_id`) REFERENCES `actor` (`actor_id`) ON UPDATE CASCADE)

我不知道这是什么意思，但我想删除该行，有什么方法可以解决这个问题。这是架构和表的快照。
代码:

public class GUI extends JFrame {

    public GUI() {
        super("Frame");
        setLayout(new FlowLayout());

        JButton b1 = new JButton("Click Delete Row");
        b1.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {

                try {

                    Connection conn = DriverManager.getConnection("jdbc:mysql://localhost/cinema", "hussnain", "toot");

                    String query = "delete from sakila.actor where actor_id=3";
                    PreparedStatement pre = conn.prepareStatement(query);

                    pre.executeUpdate();
                    JOptionPane.showMessageDialog(null, "Query Executed");
                } catch (Exception e1) {
                    JOptionPane.showMessageDialog(null, e1.getMessage());

                    e1.printStackTrace();
                }

            }

        });

        add(b1);

        setSize(400, 200);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setLocationRelativeTo(null);
        setVisible(true);

    }

}

主要方法

public class Main {

    public static void main(String[] args) {

        GUI obj = new GUI();


    }

}

Answer 1

您对 film_actor 表有外键约束，因此在从 actor 表中删除之前，您应该首先从 film_actor 表中删除。

您也可以禁用外键检查，但这会导致数据不一致；

SET FOREIGN_KEY_CHECKS=0; -- disable
SET FOREIGN_KEY_CHECKS=1; -- re-enable