整合springdatajpa
pom文件引入依赖
| <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.0.0.RELEASE</version> </parent> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-data-jpa</artifactId> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> </dependencies> |
创建User实体类
| @Entity(name = "users") public class UserEntity { @Id @GeneratedValue(strategy = GenerationType.IDENTITY) private Integer id; @Column(name = "name") private String name; @Column(name = "age") private Integer age; } |
创建UserDao
| public interface UserDao extends JpaRepository<User, Integer> { } |
创建IndexController
| @RestController public class IndexController { @Autowired private UserDao userDao;
@RequestMapping("/jpaFindUser") public Object jpaIndex(User user) { Optional<User> userOptional = userDao.findById(user.getId()); User reusltUser = userOptional.get(); return reusltUser == null ? "没有查询到数据" : reusltUser; }
} |
启动项目
| @SpringBootApplication public class JpaApp {
public static void main(String[] args) { SpringApplication.run(JpaApp.class, args); }
} |
Repository 接口
Repository 接口是 Spring Data JPA 中为我我们提供的所有接口中的顶层接口 Repository 提供了两种查询方式的支持
1)基于方法名称命名规则查询
2)基于@Query 注解查询
方法名称命名规则查询
规则:
findBy(关键字)+属性名称(属性名称的首字母大写)+查询条件(首字母大写)
| 关键字 | 方法命名 | sql where 字句 |
|---|---|---|
| And | findByNameAndPwd | where name= ? and pwd =? |
| Or | findByNameOrSex | where name= ? or sex=? |
| Is,Equal | findById, | findByIdEquals |
| Between | findByIdBetween | where id between ? and ? |
| LessThan | findByIdLessThan | where id < ? |
| LessThanEqual | findByIdLessThanEquals | where id <= ? |
| GreaterThan | findByIdGreaterThan | where id > ? |
| GreaterThanEqual | findByIdGreaterThanEquals | where id > = ? |
| After | findByIdAfter | where id > ? |
| Before | findByIdBefore | where id < ? |
| IsNull | findByNameIsNull | where name is null |
| isNotNull,Not Null | findByNameNotNull | where name is not |
| Like | findByNameLike | where name like ? |
| NotLike | findByNameNotLike | where name not like ? |
| StartingWith | findByNameStartingWith | where name like '?%' |
| EndingWith | findByNameEndingWith | where name like '%?' |
| Containing | findByNameContaining | where name like '%?%' |
| OrderBy | findByIdOrderByXDesc | where id=? order by x desc |
| Not | findByNameNot | where name <> ? |
| In | findByIdIn(Collection<?> c) | where id in (?) |
| NotIn | findByIdNotIn(Collection<?> c) | where id not in (?) |
| True | findByAaaTue | where aaa = true |
| False | findByAaaFalse | where aaa = false |
| IgnoreCase | findByNameIgnoreCase | where UPPER(name)=UPPER(?) |