springData__jpa对数据库进行操作---dao接口和 测试类

一、dao接口

采用方法命名规则，对数据库进行操作

前提是接口必须继承 JPARepository类

package cn.dzl.jpa.dao;

import cn.dzl.jpa.entity.Customer;
import org.springframework.data.jpa.repository.JpaRepository;

import java.util.List;

public interface CustomerDao extends JpaRepository<Customer,Long> {
    //方法命名规则
    public Customer findByCustId(long id);
    //模糊查询
    public List<Customer>findByCustNameLike(String CustName);
    //删除
    public void deleteByCustId(long id);
    //多条件模糊查询
    public List<Customer>findByCustNameLikeAndCustAddressLike(String CustName,String CustAddress);
    //查数
    public long count();
    //通过姓名查找
    public List<Customer> findByCustName(String custName);
}

　　二、测试类

import cn.dzl.jpa.dao.CustomerDao;
import cn.dzl.jpa.entity.Customer;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.annotation.Commit;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import org.springframework.transaction.annotation.Transactional;

import java.util.List;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:applicationContext.xml")
public class JpaTest {
    @Autowired
    CustomerDao customerDao;
    @Test
    public void findById(){
        Customer customer = customerDao.findByCustId(6L);
        System.out.println(customer);
    }
    //模糊查询
    @Test
    public void findByCustNameLike(){
        List<Customer> customerList = customerDao.findByCustNameLike("%aa%");
        for (Customer customer : customerList) {
            System.out.println(customer);
        }
    }
    //删除
    @Test
    public void deleteByCustId(){
        customerDao.deleteByCustId(5L);
        Customer customer = customerDao.findByCustId(5L);
        if (customer==null){
            System.out.println("删除成功");
        }else{
            System.out.println("删除失败");
        }
    }

    //模糊查询
    @Test
    public void findByCondition(){
        List<Customer> customerList = customerDao.findByCustNameLikeAndCustAddressLike("%哈%", "%金%");
        for (Customer customer : customerList) {
            System.out.println(customer);
        }
    }
    //查数
    @Test
    public void count(){
        long count = customerDao.count();
        System.out.println(count);

    }
    //保存
    @Test
    public void save(){
        Customer customer = new Customer();
        customer.setCustName("aa");
        customer.setCustPhone("123456");
        customer.setCustLevel("5");
        customer.setCustAddress("郑州");
        customer.setCustSource("未知");
        customerDao.save(customer);
        List<Customer> customerList = customerDao.findByCustName("aa");
        if (customerList!=null){
            System.out.println("添加成功");
            for (Customer customer1 : customerList) {
                System.out.println(customer1);
            }
        }else{
            System.out.println("添加失败");
        }

    }
}

原文地址：https://www.cnblogs.com/Hubert-dzl/p/11652464.html