基于springBoot使用JPA

1.通过maven引入相关的jar包依赖

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>

2.配置pojo（实体对象）：

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;

@Entity   //申明是个pojo对象
@DynamicUpdate    //动态更新，
@Data            //引入lombok包，可自动生成getter/setter/toString等方法
public class ProductCategory {
    @Id         //设置主键
    @GeneratedValue(strategy = GenerationType.IDENTITY)     //自增属性，strategy表示自增策略
    private Integer categoryId;
    private String categoryName;
    private Integer categoryType;

    public ProductCategory() {
    }

    public ProductCategory(String categoryName,Integer categoryType){
        this.categoryName=categoryName;
        this.categoryType=categoryType;
    }
}

3.spring-data-jpa封装了基本的增删改查可直接使用：

（Dao层）

package com.yzy.sell.Repository;

import com.yzy.sell.Entity.ProductCategory;
import org.springframework.data.jpa.repository.JpaRepository;

import java.util.List;

public interface ProductCategoryRepository extends JpaRepository<ProductCategory,Integer> {
    List<ProductCategory> findByCategoryIdIn(List<Integer> categoryTypeList); //自定义的根据类目查询，方法需命名规范
}

测试：

package com.yzy.sell.Repository;

import com.yzy.sell.Entity.ProductCategory;
import org.junit.Assert;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Optional;

import static org.junit.jupiter.api.Assertions.*;


@RunWith(SpringRunner.class)
@SpringBootTest
public class ProductCategoryRepositoryTest {

    @Autowired
    private ProductCategoryRepository repository;

    @Test
    public void testFindOne(){
        ProductCategory productCategory = repository.findById(1).get();
        System.out.println(productCategory);
    }
    @Test
    public void testFindAll(){
        List<ProductCategory> all = repository.findAll();
        System.out.println(all);
        Assert.assertNotNull(all);
    }
    @Test
    public void testSave(){
        //新增
        ProductCategory productCategory=new ProductCategory("男女必买",10);
        ProductCategory result = repository.save(productCategory);
        Assert.assertEquals(productCategory,result);
        //修改
        ProductCategory category = repository.findById(1).get();
        category.setCategoryName("男人必买");
        repository.save(category);
    }

    @Test
    public void testFindByCategoryType(){
        List<ProductCategory> byCategoryIdIn = repository.findByCategoryIdIn(Arrays.asList(1, 2, 3, 10));
        System.out.println(byCategoryIdIn);



    }
}