SpringBoot_持久化方案_JPA

最新推荐文章于 2020-11-26 07:35:05 发布

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本文详细介绍了如何在SpringBoot项目中整合JPA进行数据持久化操作，包括pom.xml依赖配置、bootstrap.yml配置、实体类定义、Repository接口编写等关键步骤，以及通过示例代码展示如何执行原生SQL、分页查询和使用自定义参数。

SpringBoot_持久化方案_JPA

依赖pom.xml
配置文件bootstrap.yml
配置源码

额外需要数据连接池配置提供DataSource对象

依赖pom.xml

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

配置文件bootstrap.yml

spring.jpa.properties.hibernate.hbm2ddl.auto=update
spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.MySQL5InnoDBDialect
spring.jpa.show-sql= true

配置源码

@SpringBootApplication
@EntityScan("com.plxc.domain")//扫描实体类
public class Main {
	public static void main(String[] args) throws Exception {
		SpringApplication.run(Main.class, args);
	}

}

//DAO层定义示例代码一
public interface JpaTbUserRepository extends JpaRepository<JpaTbUser, Integer>{
	@Query(value = "select * from tb_user b where b.mobile=?1", nativeQuery = true)
	List<JpaTbUser> findList(String username);
}

//示例代码二、执行原生SQL
public interface TransactionRepository extends JpaRepository<Transaction, Long> {
    @Query(value ="select * from transaction where id>?1 limit ?2", nativeQuery = true)
    List< Transaction > getTransactions(Integer startIndex, Integer limit);
}

//示例代码三、
//①构建PageRequest对象
Order nameOrder = new Order(Direction.DESC, "sname");
Order rangeOrder = new Order(Direction.ASC, "rangeMileage");
List<Order> orders = new ArrayList<Order>();    
orders.add(nameOrder);//先按线路降序
orders.add(rangeOrder);//再按里程升序
Sort sort2 = new Sort(orders);
Pageable pageable = new PageRequest(pageNum, size, sort2);
//②分页查询
public interface UserRepository extends JpaRepository<User, Long> {
	 @Query(value = "SELECT * FROM USERS WHERE LASTNAME = ?1",
	 countQuery = "SELECT count(*) FROM USERS WHERE LASTNAME = ?1",nativeQuery = true)
	 Page<User> findByLastname(String lastname, Pageable pageable);
}

//示例代码三、使用自定义参数名
public interface UserRepository extends JpaRepository<User, Long> {
	@Query("select u from User u where u.firstname = :firstname or u.lastname = :lastname")
	User findByLastnameOrFirstname(@Param("lastname") String lastname, @Param("firstname") String firstname);
}

//示例代码四、约定抽象函数的命名
public interface ResourceRepository extends JpaRepository<Resource, Long> {
	public List<Resource> findByUrl(String url);
}

/**
 * 用户实体类
 * 
 * @author vander
 *
 */
@Data
@Entity
@Table(name="tb_user") //指定数据库表名
@JsonIgnoreProperties(value={"hibernateLazyInitializer","handler","fieldHandler"}) 
public class JpaTbUser implements Serializable{
	private static final long serialVersionUID = 1L;
	@Id
	//@GeneratedValue( strategy = GenerationType.IDENTITY) //自增主键需配置
	private long userId;
	private String username;
	private String mobile;
	//@Column(name="pw") //变量并如果跟数据字段不一致需要注解指定
	private String password;
	private Date createTime;
}