I have a user defined class CostMatrix this class contains two properties and data type for both properties is HashMap. I am using Morphia to communicate with mongodb so my entity class looks like this
#Entity(value = "CostMatrix",noClassnameStored = false)
public class CostMatrix {
#Id
private String id;
private HashMap<String,Double> distances;
private HashMap<String,Double> durations;
public CostMatrix(){}
public CostMatrix(String id, HashMap<String,Double>distances, HashMap<String,Double>durations) {
this.id = id;
this.distances = distances;
this.durations = durations;
}
I am unable to store object properly into database object is stored any how but when I retrieve its just returns id and class name any thoughts would be appreciated.
if you don't want to have any class/package names in your collection just put the noClassnameStored flag to true.
#Entity(value = "CostMatrix",noClassnameStored =**true**)
As for the saving part, do you fill some values into your maps? The mapper will ignore null values and empty lists.
Related
I am writing an API where I am inserting a record into a table (Postgres). I was hoping to use JPA for the work. Here is the potential challenge: the primary key for the insert is generated from a database trigger, rather than from sequence count or similar. In fact, the trigger creates the primary key using the values of other fields being passed in as part of the insert. So for example,
if I have a entity class like the following:
#Entity
#Validated
#Table(name = "my_table", schema="common")
public class MyModel {
#Id
#Column(name = "col_id")
private String id;
#Column(name = "second_col")
private String secCol;
#Column(name = "third_col")
private String thirdCol;
public MyModel() {
}
public MyModel(String id, String secCol, String thirdCol) {
this.id = id;
this.secCol = secCol;
this.thirdCol = thirdCol;
}
}
I would need the col_id field to somehow honor that the key is generated from the trigger, and the trigger would need to be able to read the values for second_col and third_col in order to generate the primary key. Finally, I would need the call to return the value of the primary key.
Can this be done with jpa and repository interface such as:
public interface MyRepo extends JpaRepository <MyModel, String> {
}
and then use either default save method such as myRepo.saveAndFlush(myModel) or custom save methods? I can't find anything on using JPA with DB triggers that generating keys. If it cannot be done with JPA, I would be grateful for any alternative ideas. Thanks.
ok, I was able to get this to work. It required writing a custom query that ignored the primary key field:
public interface MyRepo extends JpaRepository <MyModel, String> {
#Transactional
#Modifying
#Query(value = "INSERT INTO my_table(second_col, third_col)", nativeQuery = true)
int insertMyTable(#Param("second_col") String second_col, #Param("third_col") String third_col);
}
The model class is unchanged from above. Because it was executed as a native query, it allowed postGres to do its thing uninterrupted.
A classic DDD rule is that aggregates should reference each other via their ID, and that the ID of an aggregate should be a value object. So something like this (in Java):
class MyAggregate {
private MyAggregateId id;
private String someOtherField;
...
}
class MyAggregateId {
private UUID id;
}
How can i make MongoDB use MyAggregateId instead of the autogenerated ObjectID? Is that possible?
Bonus points if the answer involves doing this with spring-boot, where i hoped i could just declare public interface MyAggregateRepository extends MongoRepository<MyAggregate, MyAggregateId> {} but that does not seem to work.
I want to update a MongoDB document containing a dbrf lazy attribute using spring data.
First of all, I load the existing document, I change the attributes I want and after that, I call #Repository save method, but when I check the document in MongoDB the dbrf lazy attribute is null.
I tried to load the attribute before by calling getAttribute, but that doesn't fix the problem.
Someone could help me?
Thanks
I have the Collection below:
#Data
#Document(collection = "calendriers")
public class CalendrierEntity {
#Id
#AutoGenerate(SequanceKey.CALENDRIER)
private Long id;
#NotNul
private String label;
#NotNull
private HorairesEntity horairesEntity;
#DBRef(lazy = true)
#CascadeSave
#Getter(AccessLevel.NONE)
private List<AbsenceEntity> absenceEntities;
}
and the repository bellow :
#Repository
public interface AbsenceRepository extends MongoRepository<CalendrierEntity, Long> {
AbsenceEntity findById(Long enfantId, LocalDate localDate);
}
I have calendrier document with Id 1L and want to update his label.
The calendrier document have allready a list of Absences.
this my code to update the label.
#Transactional
public void updateLabelCalendrier(Long id, String label){
CalendrierEntity calendrier = calenderRepository.findById(1L);
calendrier.setLabel(label);
calenderRepository.save(calendrier);
}
but when i check data in mongodb, i have the new label but my list of absences became null.
I'm using OpenJPA with QueryDSL, I try to avoid manipulating Tuple objects by using the bean projections features of QueryDSL. I have for example these two Entity, with a #ManyToOne relation.
#Entity
public class Folder {
private Long id;
private String name;
private String path;
#ManyToOne
#JoinColumn(name = "FK_FILE_ID")
private File file;
}
#Entity
public class File {
private Long id;
private String fileName;
}
When I'm executing this query :
List<Folder> listFolders = query.from(folder)
.list(Projections.bean(Folder.class, folder.name, folder.file.fileName));
I have an error saying that the Folder object doesn't contain the fileName property.
I understand what QueryDSL is doing, since it is a simple "flat" projection, but I would like to know if it is possible to fill the fileName attribute of my folder.file object with the found value by the query.
NB : I know that I can define a constructor for my Folder class and use this method :
query.list(ConstructorExpression.create(Folder.class, folder.name,
folder.file.fileName));
But I want to avoid this if possible, because it forces me to define N-constructors, for the N-combinations of fields I want in my projections.
You can use nested projections for this case
List<Folder> listFolders = query.from(folder)
.list(Projections.bean(Folder.class, folder.name,
Projections.bean(File.class, folder.file.fileName).as("file")));
Here is a more explicit alternative to constructor and bean projection that should also work for this case
MappingProjection<Folder> mapping = new MappingProjection<Folder>(Folder.class, folder.name, folder.file.fileName) {
#Override
protected Folder map(Tuple row) {
Folder f = new Folder();
f.setName(row.get(folder.name));
File file = new File();
file.setFileName(row.get(folder.file.fileName));
f.setFile(file);
return f;
}
};
Related
http://www.querydsl.com/static/querydsl/3.6.0/apidocs/com/mysema/query/types/MappingProjection.html
I am working with Spring MongoDb.
I create various entities using insert method:
http://docs.spring.io/spring-data/mongodb/docs/current/api/org/springframework/data/mongodb/core/MongoOperations.html#insert-java.lang.Object-
However, all methods return void. I need to return the ObjectId of the inserted document.
What is the best way to get it?
This is pretty interesting and thought I would share. I just figured out the solution for this with the help of BatScream comment above:
You would create an object and insert it into your MongoDB:
Animal animal = new Animal();
animal.setName(name);
animal.setCat(cat);
mongoTemplate.insert(animal);
Your animal class looks like this with getters and settings for all fields:
public class Animal {
#Id
#JsonProperty
private String id;
#JsonProperty
private String name;
#JsonProperty
private String cat;
public String getId() {
return id;
}
}
AFTER you have done the insert under mongoTemplate.insert(animal);, you can actually call the method animal.getId() and it will return back the ObjectId that was created.
I had the same problem with #AlanH that animal.getId() is null. And then I just realized my id field had been set as a final field with a wither method. So of course getId() is null since the id field is immutable and the wither method returns a new object with id.
if this is the case: use animal = template.insert(animal).