JDBC筆記

1.新建專案（java）JDBCDome

2.新建包（lib）

        匯入兩個JAR

            （1）連線資料庫

            （2）測試的[email protected]

3.新建一個包jdbc.pojo

User實體類

public class User{

       private Long id;

       private String userName;

       private String passWord;

              // set,get方法
}

4.新建一個包jdbc.connection

資料庫連結類Connection                     

public class Connection{
     //資料驅動
    private String driver="com.mysql.jdbc.Driver";
    //連結本機資料庫
    private String  url="jdbc:mysql://localhost:3306/資料庫";
    private String  userName="資料庫名";
    private String  passWord="資料庫密碼";
    private Connection connection=null;
    public Connection getConnection(){
         try {

            Class.forName(driver);
            connection= DriverManager.getConnection(url,userName,passWord);

        } catch (ClassNotFoundException e) {

            e.printStackTrace();
            System.out.println("資料庫載入錯誤");

        } catch (SQLException e) {

            e.printStackTrace();
            System.out.println("資料庫載入錯誤");

                    }
             return connection;

 }
}
 

資料資源類jdbcDataSource類         

public class jdbcDataSource{   
 //增刪改查
    JdbcConnectin jdbcConnectin=new JdbcConnectin();
    Connection connection=jdbcConnectin.getConnection();
    PreparedStatement ps=null;//執行sql語句
     //資料插入方法
    public void insertUser(User user){

        String insertUserSql="insert into db_user (user_name,password) values(?,?)";
         try {

            ps=connection.prepareStatement(insertUserSql);
            ps.setString(1, user.getUserName());//=?(1)
            ps.setString(2, user.getPassWord());
            ps.executeUpdate();//重新整理資料庫
             } catch (SQLException e) {
                e.printStackTrace();
                System.out.println("插入使用者錯誤");
                 }finally {
                       try {
                         ps.close();
                            } catch (SQLException e) {
                                e.printStackTrace();
                                System.out.println("預編譯語句編譯錯誤");
                                             }
                       try {

                                  connection.close();
                            } catch (SQLException e) {
                                e.printStackTrace();
                                System.out.println("關閉資料連線錯誤");
                                }
                       }
            }

     /**
     * 根據id刪除使用者
     *
     * @param id
     */

    public void deleteUser(Integer id) {

        String deleteUserSql = "delete  from user where id=?";

        try {

            ps = connection.prepareStatement(deleteUserSql);
            ps.setInt(1, id);
            ps.executeUpdate();

        } catch (SQLException e) {

            e.printStackTrace();
            System.out.println("資料插入失敗");

        } finally {

            if (ps != null) {
                try {
                    ps.close();

                } catch (SQLException e) {

                    e.printStackTrace();
                    System.out.println("資源關閉異常");

                }

                try {

                    connection.close();
                } catch (SQLException e) {

                    e.printStackTrace();
                    System.out.println("資料庫連線關閉異常");

                }
            }

        }

    }

    /**
     * 更新使用者資訊
     *
     * @param user
     */

    public void updateUser(User user) {

        String updateUserSql = "update user set user_name=?,pass_word=?where id=?";

        try {

            ps = connection.prepareStatement(updateUserSql);
            ps.setString(1, user.getUserName());
            ps.setString(2, user.getPassWord());
            ps.setInt(3, user.getId());
            ps.executeUpdate();
        } catch (SQLException e) {

            e.printStackTrace();
            System.out.println("資料插入失敗");

        } finally {

            if (ps != null) {

                try {
                    ps.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                    System.out.println("資源關閉異常");
                }

                try {
                    connection.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                    System.out.println("資料庫連線關閉異常");

                }
            }

        }

    }

    public List<User> findAllUser() {

        List<User> users = new ArrayList<User>();
        String selectAllUserSql = "SELECT *from user";
        try {
            ps = connection.prepareStatement(selectAllUserSql);
            ResultSet rs = ps.executeQuery();
            while (rs.next()) {

                User user = new User();
                user.setId(rs.getInt(1));
                user.setUserName(rs.getString(2));
                user.setPassWord(rs.getString(3));
                users.add(user);
            }

        } catch (SQLException e) {

            e.printStackTrace();
            System.out.println("資料插入失敗");

        } finally {

            if (ps != null) {

                try {

                    ps.close();

                } catch (SQLException e) {

                    e.printStackTrace();

                    System.out.println("資源關閉異常");
                }
                try {
                    connection.close();

                } catch (SQLException e) {

                    e.printStackTrace();
                    System.out.println("資料庫連線關閉異常");

                }
            }

        }
        return users;
        }
   }
 

4.進行程式測試

建包jdbc.test

             Test類                 

   public class Test{
        //載入資料來源
        JdbcDataSource jdbcDataSource=new JdbcDataSource();

    @Test//測試方法執行入口
    public void findAllUser(){

        List<User> users=new ArrayList<>();
        users=jdbcDataSource.findAllUser();
          for(User u:users){

          System.out.println(u.getId());
      }

    }

    @Test
    public void updateUser(){

        User user=new User();
        user.setId(3);
        user.setUserName("xiaohuang");
        user.setPassWord("1212");
        jdbcDataSource.updateUser(user);

    }

    @Test
    public void deleteUser(){

        int userId=2;
        jdbcDataSource.deleteUser(userId);
    }

    @Test
    public void insert(){

        User user =new User();
        user.setUserName("xiaoming");
        user.setPassWord("123");
        jdbcDataSource.insertUser(user);
        User user =new User("xiaohua","123");
        jdbcDataSource.insertUser(user);
      }

}

5.一個數據流程結束