PrepareStatement完成增删改操作

public static void main(String[] args) {
        Connection conn = null;
        PreparedStatement ps = null;
        try {
            Class.forName("com.mysql.cj.jdbc.Driver");
            conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/test?serverTimezone=UTC","root","root");
            //获取预编译的数据库操作对象
//            String sql ="insert into t_user(loginName,loginPwd) values(?,?)";
//            ps = conn.prepareStatement(sql);
//            ps.setString(1,"元歌");
//            ps.setInt(2,123);

            //update
//            String sql = "update t_user set loginPwd = ? where loginName = ?";
//            ps = conn.prepareStatement(sql);
//            ps.setString(1,"123");
//            ps.setString(2,"李白");
            //delete
            String sql ="delete from t_user where loginName = ?";
            ps = conn.prepareStatement(sql);
            ps.setString(1,"李白");
            //执行sql语句
            int count =ps.executeUpdate();
            System.out.println(count);
        } catch (ClassNotFoundException | SQLException e) {
            e.printStackTrace();
        }finally {
            try {
                if (ps!=null){
                    ps.close();
                }
            } catch (SQLException e) {
                e.printStackTrace();
            }
            try {
                if (conn!=null){
                    conn.close();
                }
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }