How do I only save a certain field/property of an Entity for another entity?
I have a Key entity with id and name properties.
In my Door entity, I would like to accept a Key but only save in the database the id
Is that possible?
Have a look at the #Transient annotation. Example from the docs:
#Entity
public class Employee {
#Id int id;
#Transient User currentUser;
...
}
#Transient will mark the annotated element to not be persisted.
Related
I have a "document" field that needs to be a primary key and must be unique, but every time I do a POST with the same document it updates the document and doesn't send a BAD_REQUEST
My entity:
#Entity
#Data
#NoArgsConstructor
#AllArgsConstructor
#Table(uniqueConstraints={#UniqueConstraint(columnNames={"document"})})
public class Cliente {
#Id
#Column(unique=true, updatable = false)
#NotBlank #NotNull
private String document;
#NotBlank
private String name;
#NotNull
private LocalDateTime date;
}
When I try to make a new POST with the same document it just updates what is saved in the database.
"Hibernate: update client set date=?, name=? where document=?"
The problem is that Spring Data JPA, when you call Repository#save, assumes that you want to update an existing entity when the passed in entity object has the id attribute set. You will have to inject a EntityManager in your code and instead call EntityManager#persist if you want to make sure that Hibernate tries to do an insert, in which case you'd get a constraint violation exception, just as you expect.
I am trying to create new table and join with ManyToOne relation with my existing table
below is my implementation
New table
#Entity(name="request_city_id")
#Table(uniqueConstraints={#UniqueConstraints{columnNames={"request_id","cityId"})})
#Data
#NoArgsConstructor
#FieldDefault(level=AccessLevel.PRIVATE)
public class RequestCityId{
#GenratedValue(strategy=SEQUENCE, generator="seq_req_city_id")
#SequenceGenerator(name="seq_req_city_id", allocationSize=1)
#Column(name="rc_id")
#Id
long id;
#ManyToOne
#JoinColumn(name="request_id")
Request request;
String cityId;
String status
}
Existing table
#Entity(name="request")
#Data
#NoArgsConstructor
#FieldDefault(level=AccessLevel.PRIVATE)
public class Request{
String frequency
#GenratedValue(strategy=SEQUENCE, generator="seq_req_d")
#SequenceGenerator(name="seq_req_id", allocationSize=1)
#Column(name="request_id")
#Id
long id;
#OneToMany(cascade={ PERSIST, MERGE}, mappedBy="request", fetch=EAGER)
Set<RequestCityId> requestCityIds;
}
but when I am trying to insert into my new table I see my hibernate query gets stuck and just gets timed out after sometime, I am not sure what I am doing wrong here? If I just kep cascade type MERGE then getting
Hibernate Error: a different object with the same identifier value was already associated with the session
First you should create an getters and setters method to each entity.
Request Class
Request City Id Class
this code creates the tables and also saves the data into the table.
Using #Data in entity classes in not recommended because it may cause some problems with jpa as mentioned here.
I have two entities Estate and PropertyTags in a Spring Boot application. The Estate entity has a many-to-many relationship with the PropertyTag (PropertyTag is also used by other entities)
This is the Estate entity:
#Entity
public class Estate{
#Id
private Long id;
.
.
#ManyToMany
private Set<PropertyTag> propertyTags;
.
.
// other properties
}
And the PropertyTag class:
#Entity
public class PropertyTag{
#Id
private Long id;
private String tagName;
// getters and setters
}
The above relationship created 3 database tables with one table for foreign keys of the relationship.
I need a repository method (or query) that will retrieve an Estate that will take and argument of an estate Id and property tag object.
I tried using the hibernate keywords as below:
public interface EstateRepository extends JpaRepository<Estate, Long> {
Optional<Estate> findByIdAndPropertyTagsContaining(Long estateId, PropertyTag childTag);
}
But that did not work.
I do not want to retrieve an estate via its ID and manually loop through its property tags to check if a tag exists in its collection. I feel this can be done with a query of the database
I am not so good at writing custom queries. I need help with the query to do that.
Thank you.
To get an Estate entity by the PropertyTag entity you can also just use the id of the PropertyTag and try
Optional<Estate> findByIdAndPropertyTags_Id(Long estateId, Long propertyTagId);
Which should return the Estate containing a tag with the given ID.
Containing is used for String searching
I see in most of the coders save data(using spring data) as:
savedEntity = repo.save(savedEntity);
Long id = savedEntity.getId();
I am confused about why most of them assign back the returned value to the saved Entity while the following code also works exact(I have tested myself):
repo.save(savedEntity);
Long id = savedEntity.getId();
Did I miss some benefit of assigning back?
for example, let the entity be:
#Entity
public class SavedEntity {
#Id
private int id;
private String name;
//getter, setters, all arg-constructor, and no-arg constructor
}
Consider the object of SavedEntity is
SavedEntity entity = new SavedEntity(1,"abcd");
now for your first question,
SavedUser entity1 = repo.save(entity);
Long id = entity1.getId();
this entity1 object is the return object getting from the database, which means the above entity is saved in the database succesfully.
for the Second Question,
repo.save(entity);
Long id = entity.getId();//which you got it from SavedEntity entity = new SavedEntity(1,"abcd");
here the value of id is the integer you mentioned in place of id(the raw value).
Most of the time the id (primary key) is generated automatically while storing the entity to the database using strategies like AUTO, Sequence etc. So as to fetch those id's or autogenerated primary key values we assign back the saved entity.
For example:
#Entity
public class Customer {
#Id
#GeneratedValue(strategy=GenerationType.AUTO)
private Long id;
private String firstName;
private String lastName;
}
In this case you'll not pass the id externally but it will create a value for it automatically while storing the data to DB.
I am using Spring Boot as my backend framework and I have a PERSON entity which has a one-to-one relation with GENDER entity.
I am using #RepositoryRestResource for PersonRepository and GenderRepository.
The GENDER table is already filled with two records of MALE and FEMALE and I have an angular form which creates a new PERSON.
In angular form, there is a list of genders with two items gotten from GenderRepository (male/female). how can I put the genderId in JSON of POST Request body to create a new Person.
I see that most of people use text/uri-list to update existing records however I want to set it while creating not updating.
You can do that by giving a link to the gender entity.
Person Entity
#Entity
public class Person {
#Id
#GeneratedValue
private Long id;
#OneToOne
private Gender gender;
//Other columns and getter/setters are removed for brevity
}
Gender Entity
#Entity
public class Gender {
#Id
#GeneratedValue
private Long id;
#Column
private String gender;
}
The following POST request to localhost:8080/api/persons with Content-Type header set to application/json creates a new Person entity and sets it's gender to the Gender with the id of 1.
{
"name": "Mahsum",
"surname": "Demir",
"gender": "http://localhost:8080/api/genders/1"
}