标题java日记
Day10
对所写的音乐管理系统的用户管理系统进行增查改,并进行了排版调整
查
public List findall() throws SQLException {
List users = new ArrayList<>();
Connection connection = DBUtil.getConnection();
PreparedStatement statement = connection.prepareStatement(“SELECT * FROM user”);
ResultSet resultSet = statement.executeQuery();
while (resultSet.next()) {
int id = resultSet.getInt(1);
String username = resultSet.getString(2);
String password = resultSet.getString(3);
User user = new User();
user.setId(id);
user.setUsername(username);
user.setPassword(password);
users.add(user);
}
return users;
case1
List users=userDao.findall();
System.out.println(users);
增
public void add(User user) throws SQLException {
Connection connection=DBUtil.getConnection();
PreparedStatement statement = connection.prepareStatement(“insert into user (username,password)values(?,?)”);
statement.setString(1,user.getUsername());
statement.setString(2,user.getPassword());
statement.executeUpdate();
case2
System.out.println(“请输入注册用户名:”);
String n=input.next();
System.out.println(“请输入注册密码:”);
String au=input.next();
System.out.println(“请输入注册用户权限”);
int ty=input.nextInt();
User user=new User();
user.setUsername(n);
user.setPassword(au);
user.setType(ty);
userDao.zhuce(user.getUsername(),
user.getPassword(),user.getType());
改
public void update(Music music) throws SQLException {
Connection connection=DBUtil.getConnection();
PreparedStatement statement=connection.prepareStatement(“update music set musicname=’?'where id=?” );
statement.executeUpdate();
case3
System.out.println(“请输入需要修改的id”);
int id=input.nextInt();
System.out.println(“请输入要修改后的密码”);
String password=input.next();
userDao.update(id,password);
break;