I have an embedded PK object that doesn't populate the id field after persisting and flushing to the database. The ID is an auto-increment field in the database.
Now normally, I would just try a refresh, but it throws the following error:
"Entity no longer exists in the database: entity.Customers[ customersPK=entity.CustomersPK[ id=0, classesId=36 ] ]."
public class Customers implements Serializable {
#EmbeddedId
protected CustomersPK customersPK;
...
}
#Embeddable
public class CustomersPK implements Serializable {
#Basic(optional = false)
#Column(name = "id")
private int id;
#Basic(optional = false)
#NotNull
#Column(name = "classes_id")
private int classesId;
.....
}
And here's the code that makes the call
Classes cl = em.find(Classes.class, classId);
CustomersPK custPK = new CustomersPK();
custPK.setClassesId(cl.getId());
Customers cust = new Customers(custPK);
em.persist(cust);
em.flush();
// The problem is right here where id always equals 0
int id = cust.getCustomerspk().getId();
Thanks for the help.
Why would the id not be 0, you have never set it?
If it is a generated id, you need to annotate it using #GeneratedValue, otherwise you need to set the value.
Related
I have generated master tables using liquibase. I have created the corresponding models in spring boot now I want to maintain a relation ship between those models.
I have one table called Vehicle_Type, it is already pre-populated using liquibase.
#Data
#Entity
#Table(name="VEHCILE_TYPE")
public class VehicleType {
#Id
private int id;
#Column(name="DISPLAY_NAME")
private String displayName;
#Column(name="TYPE")
private String type;
#Column(name="CREATED_DATE")
private LocalDateTime createdDate;
#Column(name="UPDATED_DATE")
private LocalDateTime updateDate;
}
now what I want to achieve is, I have one child entity, I have refer the VehicleType instance inside that entity as depicted below
#Data
#Entity
#EqualsAndHashCode(callSuper = true)
#Table(name = "NON_MSIL_VEHICLE_LAYOUT")
public class NonMsilVehicleLayout extends BaseImagesAndLayout {
#Id
#GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "NMV_SEQ")
#SequenceGenerator(sequenceName = "NON_MSIL_VEH_SEQUENCE", allocationSize = 1, name = "NMV_SEQ")
private int id;
#OneToOne(cascade=CascadeType.ALL)
#JoinColumn(name = "VEH_TYPE", referencedColumnName = "id")
private VehicleType vehicleType;
public interface VehType {
String getVehType();
}
}
The problem is when I tries to save entity NonMsilVehicleLayout, then it tries to first insert the data in VEHICLE_TYPE table also. which should not going to be happen.
I don't want that, I want JPA will pick the correct ID from VEHICLE_TYPE table and place it inside the corresponding table for NonMsilVehicleLayout, because the id of VEHICLE_TYPE table is act as foreign key in Non_Msil_Vehicle_Layout table.
log.info("Inside saveLayout::Start preparing entity to persist");
String resourceUri = null;
NonMsilVehicleLayout vehicleLayout = new NonMsilVehicleLayout();
VehicleType vehicleType=new VehicleType();
vehicleType.setType(modelCode);
vehicleLayout.setVehicleType(modelCode);
vehicleLayout.setFileName(FilenameUtils.removeExtension(FilenameUtils.getName(object.key())));
vehicleLayout.setS3BucketKey(object.key());
I know I missed something, but unable to figure it out.
You are creating a new VehicleType instance setting only the type field and set the vehicleType field of NonMsilVehicleLayout to that new instance. Since you specified CascadeType.ALL on NonMsilVehicleLayout#vehicleType, this means to Hibernate, that it has to persist the given VehicleType, because the instance has no primary key set.
I guess what you rather want is this code:
vehicleLayout.setVehicleType(
entitManager.createQuery("from VehicleType vt where vt.type = :type", VehicleType.class)
.setParameter("type", typeCode)
.getSingleResult()
);
This will load the VehicleType object by type and set that object on NonMsilVehicleLayout#vehicleType, which will then cause the foreign key column to be properly set to the primary key value.
Finally, after some workaround, I got the mistake, the column name attribute was incorrect, so I made it correct and remove the referencedColumn and Cascading.
Incorrect:
#OneToOne(cascade=CascadeType.ALL)
#JoinColumn(name = "VEH_TYPE", referencedColumnName = "id")
private VehicleType vehicleType;
Correct:
#OneToOne
#JoinColumn(name = "VEHICLE_TYPE")
private VehicleType vehicleTypes;
also I have added the annotation #Column in the referende entity VehicleImage
public class VehicleType {
#Id
#Column(name = "ID") // added this one
private int id;
}
That bit workaround solved my problem, now I have achieved what I exactly looking for.
I am using MySQL database.
In my table i there are two four primary keys, out of which one is auto incremented.
#Embeddable
public class EmployeeId implements Serializable {
/**
*
*/
private static final long serialVersionUID = 1L;
#Column(name = "id", nullable = false)//
This is just Pk in mysql table
**private int id;**
// I have tried and #GeneratedValue(strategy = GenerationType.IDENTITY),
#GeneratedValue(strategy = GenerationType.IDENTITY)
//and #GeneratedValue(strategy = GenerationType.TABLE)
//#GeneratedValue(strategy = GenerationType.AUTO, generator = "id") #SequenceGenerator(name = "id", sequenceName = "id")
**this is auto incremented and pk in mysql table**
#Column(name = "gender_key", nullable = false)
private int gender_key;
}
#Entity
#Table(name = "employee")
public class employee {
#EmbeddedId
private EmployeeId employeeId;
private String emp_name;
private String mobile_no;
employee() {
}}
public interface employeeRepository extends
JpaRepository<employee, EmployeeId> {
}
In My Controller I want id after employeeRepository.save(bean); method because i want to save that id in different db .
logger.info("gender_key is --- > "+gender_key);
But I am getting always 0 value of gender_key.
The thing which I have tried is:
bean = employeeRepository.save(bean)
int gender_key= bean.getGender_key();
logger.info("gender_keyis --- > "+gender_key);
But still the value for gender_key is 0(Zero).
Or any Query which I have to write in repository .
How I can get the auto incremented value of gender_key which is inserted into MySQL table?
Please Help.
Thanks in advance.
Your JPA #Id does not need to match the database PK column(s). So long as it is unique then that is all that matters.
From https://en.wikibooks.org/wiki/Java_Persistence/Identity_and_Sequencing:
The JPA Id does not always have to match the database table primary
key constraint, nor is a primary key or a unique constraint required.
As your an auto-increment column is guaranteed to be unique then just use gender_key as your #ID and map id as a normal column.
#Entity
#Table(name = "employee")
public class employee {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private int genderKey;
#Column
private int id;
}
To be honest I would find your schema confusing however.
I would also suggest reading the following:
https://www.javatpoint.com/java-naming-conventions
You're missing a #GeneratedValue at the id field.
Depending on its values, you're free to choose a strategy for generation, like a sequences, id tables, an automatic internal id generation.
Last but not least GenerationType.AUTO will choose one of the mentioned strategies.
See the Javadocs for javax.persistence.GeneratedValue and javax.persistence.GenerationType.
I am trying to add an entry into AttributeName:
#Entity
public class AttributeName implements Serializable
{
private static final long serialVersionUID = 1L;
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "attNameId", nullable = false)
private Long attNameId;
#Column(name = "attName", unique = true, nullable = false, length = 200)
private String attName;
#Column(name = "required", nullable = false)
private boolean required;
...
#Stateless
#LocalBean
public class AttributeNameManagerBean implements AttributeNameManagerRemote
{
#PersistenceContext(unitName = "mainPU")
private EntityManager entityManager;
public AttributeNameManagerBean()
{
}
...
I first must add this entry and use the newly created id to insert into the Attribute which stores this id (to link to an AttributeValue).
I have tried:
AttributeName savedAttName = entityManager.merge(newAttName);
entityManager.persist(newAttName); entityManager.flush();
entityManager.create(Native)Query("INSERT...");
I receive a ConstraintViolationException later but the main problem is that the insert statement in any of the 3 above forms does not throw an exception, but when I query the database the new entry is not there.
In the first example, savedAttName contains the newly generated unqiue PK :S
Note: I am sure that attName is a new unique entry into the database.]
Any help would be greatly appreciated. Happy to provide any more information if required.
Edit: There is an attNameId field in Attribute. Attribute has two unique constraints:
uniqueConstraints={
#UniqueConstraint(columnNames = {"attNameId", "attValueId"} ),
#UniqueConstraint(columnNames = {"sectionId", "sectionIndex"} )}
The sectionId and sectionIndex being entered are a unique combination which doesn't exist currently in AttributeName (which only has 1 entry, which I manually inserted).
Fix:
Removed the constraints from the table, reployed. Then dropped the table, re-added the constraints and it works. I'm guessing it didn't correctly set up the constraints.
I have one entity called Change where I need log changes in database like inserting, updating or deleting rows.
So my Change table contains some data and now I would like to add foreign key to record changes in another table, but I have different tables. For example I have Weather table, Group table,... So I have done some searching and I have found a little bit about #Any annotation. So I added some columns to my Change entity:
#Entity
#Table(name = "CHANGE")
public class Change {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
#Column(name = "CHANGE_ID")
private int changeId;
...
#Any(metaColumn = #Column(name = "RECORD_TABLE"))
#AnyMetaDef(idType = "int", metaType = "string",
metaValues = {
#MetaValue(targetEntity = Weather.class, value = "WEATHER"),
#MetaValue(targetEntity = Group.class, value = "GROUP"),
...
})
#JoinColumn(name="recordID")
private Object record;
#ManyToOne
#JoinColumn(name = "USER_ID")
private User user;
public Object getRecord() {
return record;
}
public void setRecord(Object record) {
this.record = record;
}
...
And my stupid question is:
How can I insert data into database (like foreign ID and class name) and how could I retrieve them?
Please go through this Link
You should care about your entity relationship (1-1 or 1-M or M-M)
I am getting a null pointer exception when i try to call a getter for a relationship. it is my understanding that the container will fill this field in with an appropriate list object whilst the entity is still managed.
the schema was pre-existing so this is a bottom up mapping.
This is my 'one' side entity of the onetomany relationship:
#Entity
#Table(name=CollectorHeader.TABLE_NAME)
public class CollectorHeader implements Serializable {
...
#Id
#Column(name = "COLLECTORHEADERID")
private long id;
#OneToMany(mappedBy="collectorHeader", fetch=FetchType.LAZY)
private List<CollectorDetail> collectorDetails;
...
}
And here is my 'many' side entity :
#Entity
#Table(name = CollectorDetail.TABLE_NAME)
public class CollectorDetail implements Serializable {
...
#Id
#Column(name = "COLLECTORDETAILID", unique = true)
long id;
...
#NotNull
#ManyToOne
#JoinColumn(name = "COLLECTORHEADERID")
private CollectorHeader collectorHeader;
...
public CollectorDetail(long id, #NotNull CollectorHeader collectorHeader,
long provenanceLinkPk, #NotNull String provenanceLinkClass) {
setId(id);
setCollectorHeader(collectorHeader);
setProvenanceLinkPk(provenanceLinkPk);
setProvenanceLinkClass(provenanceLinkClass);
}
}
And this is where i am calling the relationship:
public CollectorDetail createCollectorDetail(long collectorHeaderId, long provenanceLinkPk, #NotNull String provenanceLinkClass) throws SystemException {
CollectorHeader collectorHeader = em.find(CollectorHeader.class, collectorHeaderId);
if(collectorHeader == null) {
String error = "There is no Collector Header with the id: '" + collectorHeaderId + "'";
log.error(error);
throw new SystemException(error);
}
CollectorDetail collectorDetail =
new CollectorDetail(NextNumberFactory.getInstance().getNextNumberLong("cocollectordetail")
, collectorHeader
, provenanceLinkPk
, provenanceLinkClass);
collectorHeader.getCollectorDetails().add(collectorDetail); //NULLPOINTEREXCEPTION
em.merge(collectorDetail);
em.merge(collectorHeader);
return collectorDetail;
}
Sql Schema:
CREATE TABLE COCOLLECTORHEADER (
COLLECTORHEADERID DECIMAL(20,0) NOT NULL PRIMARY KEY,
COLLECTEDTIMESTAMP TIMESTAMP, -- the date when the information was collected
PROCESSEDTIMESTAMP TIMESTAMP, -- the date when the information was processed
FILEFORMAT VARCHAR(16) NOT NULL,
SEQUENCENUMBER INTEGER
);
CREATE TABLE COCOLLECTORDETAIL (
COLLECTORDETAILID DECIMAL(20,0) NOT NULL PRIMARY KEY,
COLLECTORHEADERID DECIMAL(20,0) NOT NULL
REFERENCES COCOLLECTORHEADER(COLLECTORHEADERID),
PROVENANCELINKPK DECIMAL(20,0) NOT NULL,
PROVENANCELINKCLASS VARCHAR(128) NOT NULL
);
Any assistance would be much appreciated.
Initialize collectorDetails with a valid collection object as:
private List<CollectorDetail> collectorDetails = new ArrayList<CollectorDetail>();
Also check Is it good practice to initialize fields inside a JPA entity getter?