Spring 数据 jpa 存储库查找通过返回 null 即使数据库中存在数据

Question

I am using spring data JPA, facing issue as result is always coming NULL even if record present into DB.

I tried debugging spring code and checked whether statement created correctly or not. Statement is created correctly and parameter is also populated correctly.

Configuration: - Spring-boot = 2.0.5.RELEASE

Oracle DB = Oracle Database 11g Release 11.2.0.2.0 - 64bit

POM

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
        <exclusions>
            <exclusion>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-logging</artifactId>
            </exclusion>
        </exclusions>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
    </dependency>
    <dependency>
        <groupId>org.apache.tomcat.embed</groupId>
        <artifactId>tomcat-embed-jasper</artifactId>
        <scope>provided</scope>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-log4j2</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-jpa</artifactId>
        <exclusions>
            <exclusion>
                <groupId>org.apache.tomcat</groupId>
                <artifactId>tomcat-jdbc</artifactId>
            </exclusion>
        </exclusions>
    </dependency>
    <dependency>
        <groupId>com.oracle</groupId>
        <artifactId>ojdbc7</artifactId>
        <version>12.1.0</version>
    </dependency>
</dependencies>

Entity class:

@Entity()
public class User {

    @Id
    @GeneratedValue(strategy=GenerationType.SEQUENCE, generator = "user_Sequence")
    @SequenceGenerator(name = "user_Sequence", sequenceName = "USER_SEQ")
    private Long id;
    
    @Column(unique=true)
    private String userName;
    
    private String password;
    //getter & setter

Repository class

@Repository
public interface UserRepository extends 
org.springframework.data.repository.CrudRepository<User, Long>{

    User findByUserName(String userName);
    
    User save(User user);
}

Service class

@Service("loginService")
public class LoginService implements ILoginService {

    @Autowired
    UserRepository userRepository;
    
    @Override
    public boolean isValidUser(String userName, String password) {
        User user = userRepository.findByUserName(userName);
        if(user != null && user.getUserName().equals(userName) && user.equals(password)){
            return true;
        } else {
            return false;
        }
    }
}

Debug Screenshot: - Debug Screenshot parameter value is "admin" and SQL formed

SQL Formed: -

select user0_."id" as id1_2_, user0_."password" as password2_2_, user0_."user_name" as user_name3_2_ from "user" user0_ where user0_."user_name"=?

If I run same query in DB, result is: - Result Screenshot

Answer 1

Since you are not using your column name as your field names it needs to know what to map to in your entity.

Change your field to either be user_name or change:

@Column(unique=true)
private String userName;

to

@Column(name="user_name", unique=true)
private String userName;

thus it will be able to know what column it references;

https://www.concretepage.com/spring-5/spring-data-crudrepository-example

Answer 2

在存储库中使用 findByNameEqualsAndStatus

Answer 3

Below are things that work for me. I am using Oracle 19C with org.hibernate.dialect.Oracle12cDialect.

grant all on <schema>.<table> to <user>;
grant all on <schema>.<sequence> to <user>;