表结构

id：int类型

name: varchar类型

pass: varchar类型

获得连接对象

public Connection getMySQL(){
        Connection connection = null;
        //1.注册驱动
        try {
            Class.forName("com.mysql.jdbc.Driver");
            String url = "jdbc:mysql://localhost/mybatis?characterEncoding=utf8&connectionTimeZone=Asia/Shanghai";
            connection = DriverManager.getConnection(url, "root", "root");
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return connection;
    }

新增数据

public boolean addUser(){
        boolean success = false;
        Connection conn = getMySQL();
        try {
            PreparedStatement preparedStatement = conn.prepareStatement("insert into user(name,pass) values(?,?)");
            preparedStatement.setString(1, "黑客联盟");
            preparedStatement.setString(2, "黑客联盟");
            int i = preparedStatement.executeUpdate();
            if(i>=1){
                success = true;
            }
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return success;
    }

查询数据

public List<User> queryUsers(){
        List<User> list=new ArrayList<>();
        Connection conn = getMySQL();
        try {
            Statement statement = conn.createStatement();
            ResultSet rs = statement.executeQuery("select * from user");
            while (rs.next()) {
                int id = rs.getInt("id");
                String name = rs.getString("name");
                String pass = rs.getString("pass");
                User u = new User(id,name,pass);
                list.add(u); 
            }
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return list;
    }

修改数据

public boolean updateUser(){
        boolean success = false;
        Connection conn = getMySQL();
        try {
            PreparedStatement preparedStatement = conn.prepareStatement("update user set name=?,pass=? where id=1");
            preparedStatement.setString(1, "pingchas1");
            preparedStatement.setString(2, "pingchaspass1");
            int i = preparedStatement.executeUpdate();
            if(i>=1){
                success = true;
            }
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return success;
    }

删除数据

public boolean deleteUser(){
        boolean success = false;
        Connection conn = getMySQL();
        try {
            PreparedStatement preparedStatement = conn.prepareStatement("delete from user  where id=1");
            int i = preparedStatement.executeUpdate();
            if(i>=1){
                success = true;
            }
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return success;
    }