JPA OneToOne relationships returning null The 2019 Stack Overflow Developer Survey Results Are InAvoiding != null statementsJPA EntityManager: Why use persist() over merge()?Wrong ordering in generated table in jpaIs null check needed before calling instanceof?Create the perfect JPA entityJPA/Hibernate - inverse join on unidirectional OneToOne association?What's the difference between JPA and Hibernate?What's the difference between @JoinColumn and mappedBy when using a JPA @OneToMany associationJPA: Querying a OneToOne relationship with an abstract classHibernate : Why FetchType.LAZY-annotated collection property eagerly loading?
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JPA OneToOne relationships returning null
The 2019 Stack Overflow Developer Survey Results Are InAvoiding != null statementsJPA EntityManager: Why use persist() over merge()?Wrong ordering in generated table in jpaIs null check needed before calling instanceof?Create the perfect JPA entityJPA/Hibernate - inverse join on unidirectional OneToOne association?What's the difference between JPA and Hibernate?What's the difference between @JoinColumn and mappedBy when using a JPA @OneToMany associationJPA: Querying a OneToOne relationship with an abstract classHibernate : Why FetchType.LAZY-annotated collection property eagerly loading?
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I have this class
public class Hotel implements Serializable
@OneToOne(fetch = FetchType.EAGER)
@JoinColumn(name = "FILE_ID")
private File file;
..
and this query
Query query = em.createQuery("SELECT file.hotel FROM File file where file.id = :id ");
and I would like to know if it is possible to return an empty Hotel object instead of null if the hotel does not exists in the relationship but the file exists
java spring hibernate jpa hibernate-mapping
asked Mar 8 at 11:11
carles xurigueracarles xuriguera
30713
add a comment |
I have this class
public class Hotel implements Serializable
@OneToOne(fetch = FetchType.EAGER)
@JoinColumn(name = "FILE_ID")
private File file;
..
and this query
Query query = em.createQuery("SELECT file.hotel FROM File file where file.id = :id ");
and I would like to know if it is possible to return an empty Hotel object instead of null if the hotel does not exists in the relationship but the file exists
java spring hibernate jpa hibernate-mapping
asked Mar 8 at 11:11
carles xurigueracarles xuriguera
30713
1
I think you query should be more likeSELECT hotel.file from .... And no, you can't return an empty hotel as that would still have to be in the database. The only thing you can do is use@PostLoadand check if the result is null and if so, set it to an empty hotel
– XtremeBaumer
Mar 8 at 11:18
add a comment |
I have this class
public class Hotel implements Serializable
@OneToOne(fetch = FetchType.EAGER)
@JoinColumn(name = "FILE_ID")
private File file;
..
and this query
Query query = em.createQuery("SELECT file.hotel FROM File file where file.id = :id ");
and I would like to know if it is possible to return an empty Hotel object instead of null if the hotel does not exists in the relationship but the file exists
java spring hibernate jpa hibernate-mapping
asked Mar 8 at 11:11
carles xurigueracarles xuriguera
30713
I have this class
public class Hotel implements Serializable
@OneToOne(fetch = FetchType.EAGER)
@JoinColumn(name = "FILE_ID")
private File file;
..
and this query
Query query = em.createQuery("SELECT file.hotel FROM File file where file.id = :id ");
and I would like to know if it is possible to return an empty Hotel object instead of null if the hotel does not exists in the relationship but the file exists
java spring hibernate jpa hibernate-mapping
java spring hibernate jpa hibernate-mapping
asked Mar 8 at 11:11
carles xurigueracarles xuriguera
30713
asked Mar 8 at 11:11
carles xurigueracarles xuriguera
30713
edited Mar 8 at 11:45
carles xuriguera
asked Mar 8 at 11:11
carles xurigueracarles xuriguera
30713
asked Mar 8 at 11:11
carles xurigueracarles xuriguera
30713
asked Mar 8 at 11:11
carles xurigueracarles xuriguera
30713
30713
1
I think you query should be more likeSELECT hotel.file from .... And no, you can't return an empty hotel as that would still have to be in the database. The only thing you can do is use@PostLoadand check if the result is null and if so, set it to an empty hotel
– XtremeBaumer
Mar 8 at 11:18
add a comment |
1
I think you query should be more likeSELECT hotel.file from .... And no, you can't return an empty hotel as that would still have to be in the database. The only thing you can do is use@PostLoadand check if the result is null and if so, set it to an empty hotel
– XtremeBaumer
Mar 8 at 11:18
1
1
I think you query should be more like
SELECT hotel.file from .... And no, you can't return an empty hotel as that would still have to be in the database. The only thing you can do is use @PostLoad and check if the result is null and if so, set it to an empty hotel– XtremeBaumer
Mar 8 at 11:18
I think you query should be more like
SELECT hotel.file from .... And no, you can't return an empty hotel as that would still have to be in the database. The only thing you can do is use @PostLoad and check if the result is null and if so, set it to an empty hotel– XtremeBaumer
Mar 8 at 11:18
add a comment |
1 Answer
1
active
oldest
votes
Since you're using JPA, you could make use of a repository. JPA can automatically return a type of Optional<>. Via Optional.isPresent() you can check if the query returned something.
A repository could look like this:
public interface FileRepository extends JpaRepository<File, Long>
Optional<File> findById(Long id);
answered Mar 8 at 12:43
Sige VVSige VV
317
add a comment |
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1 Answer
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active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
Since you're using JPA, you could make use of a repository. JPA can automatically return a type of Optional<>. Via Optional.isPresent() you can check if the query returned something.
A repository could look like this:
public interface FileRepository extends JpaRepository<File, Long>
Optional<File> findById(Long id);
answered Mar 8 at 12:43
Sige VVSige VV
317
add a comment |
Since you're using JPA, you could make use of a repository. JPA can automatically return a type of Optional<>. Via Optional.isPresent() you can check if the query returned something.
A repository could look like this:
public interface FileRepository extends JpaRepository<File, Long>
Optional<File> findById(Long id);
answered Mar 8 at 12:43
Sige VVSige VV
317
add a comment |
Since you're using JPA, you could make use of a repository. JPA can automatically return a type of Optional<>. Via Optional.isPresent() you can check if the query returned something.
A repository could look like this:
public interface FileRepository extends JpaRepository<File, Long>
Optional<File> findById(Long id);
answered Mar 8 at 12:43
Sige VVSige VV
317
Since you're using JPA, you could make use of a repository. JPA can automatically return a type of Optional<>. Via Optional.isPresent() you can check if the query returned something.
A repository could look like this:
public interface FileRepository extends JpaRepository<File, Long>
Optional<File> findById(Long id);
answered Mar 8 at 12:43
Sige VVSige VV
317
answered Mar 8 at 12:43
Sige VVSige VV
317
answered Mar 8 at 12:43
Sige VVSige VV
317
answered Mar 8 at 12:43
Sige VVSige VV
317
317
add a comment |
add a comment |
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I think you query should be more like
SELECT hotel.file from .... And no, you can't return an empty hotel as that would still have to be in the database. The only thing you can do is use@PostLoadand check if the result is null and if so, set it to an empty hotel– XtremeBaumer
Mar 8 at 11:18