I have a very similar question to this one, however my question is even more basic than that one and so I don't feel like its a dupe...(we'll see what SO thinks). And if it is a dupe of another question, please point out to me (perhaps in a comment) how the accepted answer completely answers/addresses my issue (I don't think it does!).
I have a Java/JPA/Hibernate #Entity class that needs to have a UUID field:
#Canonical
#MappedSuperclass
public abstract class BaseEntity {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
private UUID refId;
// Getters/setters/ctors/etc.
}
#Entity(name = "accounts")
#AttributeOverrides({
#AttributeOverride(name = "id", column=#Column(name="account_id")),
#AttributeOverride(name = "refId", column=#Column(name="account_ref_id"))
})
public class Account extends BaseEntity {
// blah whatever
}
That is, I need to be working with UUIDs at the app layer. However the database here is MySQL, and the overwhelming recommendations for representing UUIDs in MySQL seems to be to represent them as a VARCHAR(36), so that's what I have.
At runtime I'm getting the following exception:
Caused by: org.hibernate.HibernateException: Wrong column type in my_db.accounts for column account_ref_id. Found: varchar, expected: binary(255)
at org.hibernate.mapping.Table.validateColumns(Table.java:373)
at org.hibernate.cfg.Configuration.validateSchema(Configuration.java:1338)
<rest of stack trace omitted for brevity>
So clearly, the database is presenting a VARCHAR(36), but Hibernate seems to be defaulting to expect a binary(255).
I honestly don't care what the UUID gets stored as in the DB. It could be VARCHAR, it could be TEXT, it could be BLOB...it could be a toaster oven for all I care! But the essential requirement here is that the data model (the entity class) use UUIDs.
What's the fix here? If I have to change the column type in the DB, what do I change the type to? If I have to change/modify the UUID field in the entity, what else do I need to annotate it with?
For me the fix required changes to both DB schema as well as the entity (Java) code.
First I changed my CREATE TABLE statement to use BINARY(255) instead of VARCHAR(36):
CREATE TABLE IF NOT EXISTS accounts (
# lots of fields...
account_ref_id BINARY(255) NOT NULL,
# ...lots of other fields
);
Next I added #Type(type="uuid-binary") to my field declaration in the entity:
#Canonical
#MappedSuperclass
public abstract class BaseEntity {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
#Type(type="uuid-binary")
private UUID refId;
// Getters/setters/ctors/etc.
}
#Entity(name = "accounts")
#AttributeOverrides({
#AttributeOverride(name = "id", column=#Column(name="account_id")),
#AttributeOverride(name = "refId", column=#Column(name="account_ref_id"))
})
public class Account extends BaseEntity {
// blah whatever
}
This works beautifully for me.
Try it like this:
public class BaseEntity{
#Column(nullable = false)
private String uuid;
public BaseEntity(){
setUuid(UUID.randomUUID().toString());
}
public String getUuid() {
return uuid;
}
public void setUuid(String uuid) {
this.uuid = uuid;
}
#PrePersist
public void prePersist(){
if(null == getUuid())
setUuid(UUID.randomUUID().toString());
}
....
Column definition:
uuid varchar(255) DEFAULT NULL
When generating UUID use toString method:
entity.setUuid(UUID.randomUUID().toString())
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'm working with Spring Data JPA and I'm trying to create 4 different entities that will have exactly the same fields but they will be stored in 4 different tables.
This is my key class
public class IndexId implements Serializable {
private int seqNo;
private String index;
// getters and setters
}
Then I have the base class:
#MappedSuperclass
public class BaseIndex {
#Id
#Column(name = "seq_no", nullable = false)
protected int seqNo;
#Id
#Column(name = "index", nullable = false)
protected String index;
#Column(name = "value", nullable = false)
protected String value;
//getters/setters
}
Then my entity that will store in the database:
#Entity
#IdClass(IndexId.class)
#Table(name = "bibliographic_single_index")
public class BibliographicSingleIndex extends BaseIndex implements Serializable { }
This is the error I get: Persistent entity 'BibliographicSingleIndex' should have primary key .
I also tried with the properties declared as private and the articles I see on this subject seem to do the same thing.
With these pieces of code is it possible to identify what I'm doing wrong?
I believe every entity needs a separate java class for the id class. You wouldn't have the problem with embedded ids I think.
I'm mapping a relationship that does not use the entity's primary key. Using "referencedColumnName" with a column different than the primary key causes hibernate to eagerly fetch the association, by issuing an extra select, even when it's tagged with FetchType.LAZY.
My goal is to make it behave like a regular mapping, meaning it wouldn't issue an extra query every time I need to query the main entity.
I have already tried using #LazyToOne(LazyToOneOption.NO_PROXY), which sorts out the problem, but it does not operate well with Jackson's (JSON parsing library) module "jackson-datatype-hibernate5", which skips hibernate lazy proxies when serializing the results.
Here is a scenario almost like the one I have that causes the problem:
Entities:
#Entity(name = "Book")
#Table(name = "book")
public class Book
implements Serializable {
#Id
#GeneratedValue
private Long id;
private String title;
private String author;
#NaturalId
private String isbn;
//Getters and setters omitted for brevity
}
#Entity(name = "Publication")
#Table(name = "publication")
public class Publication {
#Id
#GeneratedValue
private Long id;
private String publisher;
#ManyToOne(fetch = FetchType.LAZY)
#JoinColumn(
name = "isbn",
referencedColumnName = "isbn"
)
private Book book;
#Column(
name = "price_in_cents",
nullable = false
)
private Integer priceCents;
private String currency;
//Getters and setters omitted for brevity
}
Repository (Spring-Data, but you could try directly with the EntityManager):
#Repository
public interface PublicationRepository extends JpaReadRepository <Publication, Long>
{
#Query ("SELECT d FROM Publication d WHERE d.publisher = ?1 ")
Optional <Publication> findByPublisher (String isbn);
}
Thanks
The only way to achieve what you are looking for is by moving the annotatation #Id to the isbn property.
You can leave the #GeneratedValue on the autoincrement property.
Notes:
1 - Make sure that your equals/hc are following the OID(Object ID) on your domain case the "NaturalId" ISBN.
2 - It will be good to ensure if possible on DB level that your natural ID has unique contraint on it.
I have main entity:
#Entity
#Table(name = "partners")
public class Partner {
#ElementCollection
#CollectionTable(
name = "external_login",
joinColumns = #JoinColumn(name = "partner_id")
)
private List<ExternalLogin> externalLogins;
...
}
And ExternalLogin is embeded entity
#Embeddable
public class ExternalLogin {
#Column(name = "type")
#Enumerated(value = EnumType.STRING)
private ExternalLoginType type;
#Column(name = "login")
private String login;
#Column(name = "password_value")
private String passwordValue;
}
public enum ExternalLoginType {
ABC;
}
#Column and #Enumerated not works in ExternalLogin entity.
For example in query will be external_login.passwordValue instead of external_login.password_value.
#Enumerated(value = EnumType.STRING) doesn't work too. Hibernate is trying to get int value of filed instead string.
Can anyone help me?
You misuse annotation #Embeddable. See description in oracle docs https://docs.oracle.com/javaee/6/api/javax/persistence/Embeddable.html
Defines a class whose instances are stored as an intrinsic part of an owning entity and share the identity of the entity. Each of the persistent properties or fields of the embedded object is mapped to the database table for the entit
#Embeddable annotation makes sense only for singular assotiation fields. Annotating list fields as #Embeddable is wrong.
Just replace
#Embeddable
public class ExternalLogin {
to
#Entity
public class ExternalLogin {
I had exactly the same issue just now.
The solution for me ended up being adding
#Access(FIELD)
To the Embeddable object.
I have what I thought was a straight forward relation in JPA. Looks like this. CompanyGroup:
#Entity
#Table
public class CompanyGroup implements Serializable {
private static final long serialVersionUID = 1L;
#Id
#GeneratedValue
private Long id;
#Column(name = "name")
private String name;
#JoinColumn(name = "companies")
#OneToMany(fetch = FetchType.EAGER, cascade = CascadeType.ALL)
private List<Company> companies;
}
Company:
#Entity
#Table
public class Company implements Serializable {
private static final long serialVersionUID = 1L;
#Column(name = "name")
private String name;
#JoinColumn(name = "users")
#OneToMany(fetch = FetchType.EAGER, cascade = CascadeType.ALL)
private List<User> users;
#Id
#GeneratedValue
private Long id;
}
User:
#Entity
#Table
public class User {
#Column(name = "firstName")
private String firstName;
#Column(name = "lastName")
private String lastName;
#Column(name = "email")
private String email;
#Id
#GeneratedValue
private Long id;
}
I have omitted setters, getters, etc.
This is not working. I'm trying to save a CompanyGroup(Has 2 companies, each company has 2 users, all entities are unique) to a fully empty database.
I persist this using Spring-Data, accessed in a service like this:
#Service
public class ConcreteCompanyGroupService implements CompanyGroupService {
#Autowired
private CompanyGroupRepository repository;
#Transactional
#Override
public void save(CompanyGroup group) {
repository.save(Collections.singleton(group));
}
}
When I try to call this method I receive this:
org.postgresql.util.PSQLException: ERROR: syntax error at or near "User"
Position: 13
at org.postgresql.core.v3.QueryExecutorImpl.receiveErrorResponse(QueryExecutorImpl.java:2458)
at org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:2158)
at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:291)
Hopefully I have done something stupid that someone can find quickly. I don't know how to solve this.
EDIT:
The driver in my pom.xml:
<dependency>
<groupId>org.postgresql</groupId>
<artifactId>postgresql</artifactId>
<version>9.4.1211</version>
</dependency>
Your entity maps across to a table name that is an SQL reserved keyword (User). Sadly for you, your chosen JPA provider does not automatically quote the table name identifier, and so you get exceptions when referring to the table.
Solution is either to quote the table name yourself in the #Table annotation, or change the table name to not be a reserved keyword. Alternatively use a JPA provider that auto-quotes such reserved keywords for you (e.g DataNucleus)
Solution 1: As Pascal mentioned, you have to escape the table name with backslash like:
#Entity
#Table(name="\"User\"")
public class User {
...
}
Solution 2: Rename your table's anme with another name (Users)
#Entity
#Table(name="Users")
public class User {
...
}
Solution 3: Add a suffix to the table's name:
#Entity
#Table(name="APP_User")
public class User {
...
}
Solution 4: Change the entity name, e.g. ApplicationUser
#Entity
public class ApplicationUser {
...
}
The reason
PostgreSQL as some reserved SQL Key Words. For example: ABORT, ALL, ARRAY, CACHE, CUBE, USER, ... Those tokens are in the SQL standard or specific to PostgreSQL
Use the #Table annotation or change your class name from User to something else as User is a reserved keyword in sql.