package top.qaqaq.java.P571;

import java.util.List;

/**
 * @author RichieZhang
 * @create 2022-10-28 下午 9:10
 *
 * DAO:data(base) access object
 */
public class DAO <T>{//表的共性操作的DAO

    //添加一条记录
    public void add(T t){

    }

    //删除一条记录
    public boolean remove(int index){

        return false;
    }

    //修改一条记录
    public void update(int index,T t){

    }

    //查询一条记录
    public T getIndex(int index){

        return null;
    }
    //查询多条记录
    public List<T> getForList(int index){

        return null;
    }

    //泛型方法
    //举例：获取表中一共有多少条记录？获取最大的员工入职时间？
    public <E> E getValue(){

        return null;
    }
}

package top.qaqaq.java.P571;

import org.junit.jupiter.api.Test;

import java.util.List;

/**
 * @author RichieZhang
 * @create 2022-10-28 下午 9:20
 */
public class DAOTest {

    @Test
    public void test1(){
        CustomerDAO dao1 = new CustomerDAO();

        dao1.add(new Customer());
        List<Customer> list = dao1.getForList(10);

        StudentDAO dao2 = new StudentDAO();
        Student student = dao2.getIndex(1);



    }
}

package top.qaqaq.java.P571;

/**
 * @author RichieZhang
 * @create 2022-10-28 下午 9:15
 */
public class Customer { //此类对应数据库中的customers表
}

package top.qaqaq.java.P571;

/**
 * @author RichieZhang
 * @create 2022-10-28 下午 9:16
 */
public class CustomerDAO extends DAO<Customer>{//只能操作某一个表的DAO
}

package top.qaqaq.java.P571;

/**
 * @author RichieZhang
 * @create 2022-10-28 下午 9:24
 */
public class Student {
}

package top.qaqaq.java.P571;

/**
 * @author RichieZhang
 * @create 2022-10-28 下午 9:24
 */
public class StudentDAO extends DAO<Student> {//只能操作某一个表的DAO

}