I'm trying to configure a mapped class to use a sequence I defined in a postgres db. The ids are always zero when I try to persist any entities, if I use select nextval('item_seq'), I'll get 1 (or the next val). I used intellij to regenerate the classes. The version of hibernate in this project is 3.6.0, if that might be part of my problem?
#Entity
#Table(name = "item")
public class Item {
private int itemid;
...
#Basic
#Id
#SequenceGenerator(name = "item_seq", sequenceName = "item_seq", allocationSize = 1)
#GeneratedValue(strategy=GenerationType.SEQUENCE, generator = "item_seq")
#Column(name = "itemid", unique = true, nullable = false, insertable = true, updatable = true)
public int getItemid() {
return itemid;
}
...
}
Usage
Item item = new Item();
item.setCreated(new Date());
item.setVendorId(vendorId);
save(item); // essentially is getHibernateTemplate().save(Item.class.getName(), item);
-- EDIT --
I've been trying the suggestions below and everything seems to keep generating 0 as an id or throw the exception 'ids for this class must be manually assigned before calling save()'. This is where I am now, as a last ditch effort I tried moving the annotations to the variable declaration instead of the getter. Didn't help.
#Entity
#Table(name = "item")
public class Item {
#Id
//#SequenceGenerator(name = "item_seq", sequenceName = "item_seq", allocationSize = 1)
#GeneratedValue(strategy = GenerationType.IDENTITY) //, generator = "item_seq")
#Column(name = "itemid", unique = true, nullable = false) //, insertable = true, updatable = true)
private Long itemid;
...
public Long getItemid() {
return itemid;
}
}
This always works for me (Hibernate 4.x though):
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
#Id makes the column a primary key (unique, no nulls), so you don't need the #Column(...) annotation. Is something setting your itemId somewhere? You can remove its setter if you have one (Hibernate doesn't require).
Try to provide database schema name for given table and sequence in you entity class.
Make sure your application user has privileges (grants) to the sequence.
-- update --
I think solution is here
I was having the same problem and here's what I did to solve the issue
I was using Hibernate tools to auto generate POJOs and all the annotations were being placed at the method level, however, Spring recommends (requires?) them at the field level. You can't just move the Id annotations to the field level either, because it's either one or the other (I got some other exceptions when I tried this). So I followed this answer to customize Hibernate tools to generate POJOs with the annotations all at the field level.
Now my code looks like this and it's using the database sequence sequence just fine.
#Id
#GeneratedValue(strategy=GenerationType.SEQUENCE, generator="my_seq")
#SequenceGenerator(name="my_seq",sequenceName="SPT_PROJECT_SEQ", allocationSize=1)
#Column(name = "PROJECT_ID", unique = true, nullable = false, precision = 10, scale = 0)
private long projectId;
Hope this helps
what database u are using?
can be possibly a database that does not support sequence??
try to use strategy=auto and see how does it work
since 'select nextval(...)' works, your database (postgresql) is supporting sequence. so thats not it
maybe for some reason hibernate is threating yout int == 0 as an id and it is trying to update it instead of inserting a new record ( deafult value for int =0 ) just change your id type to Integer and see if it solve the problem
Related
I have this entity, in which I have made a PUT and POST method, which do not give an error but nevertheless the idMoneda, which is a property calculated with #Transient because it is the ID of the moneda(where there is a 1 to 1 relationship with another table), it does not update me, when I look at the database it remains null even though in the POST request I put a value. I don't know if it's because the setter is wrong, or just that something else needs to be added that I don't see right now.
#Entity
#Table(name = "REMESA")
public class Remesa {
#Id
#SequenceGenerator(name = "remesa_sequence", sequenceName = "remesa_sequence", allocationSize = 1)
#GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "remesa_sequence")
#Column(name = "ID")
private Long id;
#OneToOne
#JoinColumn(name = "moneda", nullable = true)
#JsonIgnore
private Moneda moneda;
#Transient
#JsonProperty("moneda")
private Long idMoneda;
public Long getIdMoneda() {
return this.moneda.getId();
}
public void setIdMoneda(Long idMoneda) {
this.idMoneda = idMoneda;
}
}
#Transient in JPA means: do not save this field in DB. A column named "moneda_id" will automatically be generated by your relationship if it's well-defined
Java's transient keyword is used to denote that a field is not to be serialized, whereas JPA's #Transient annotation is used to indicate that a field is not to be persisted in the database, i.e. their semantics are different. Because they have different meanings.
So try to remove the transient annotation and run your code .
I am using following code to define MyEntity,
#Entity
#Table(name = "MY_TABLE")
public class MyEntity {
#Id
#GeneratedValue(strategy=GenerationType.AUTO)
#Column(name = "MY_TABLE_ID")
private Integer myTableId;
#Column(name = "MY_TABLE_NM")
private String myTableName;
//Getters Setters
}
For the first POST after my application starts, I create MyEntity everything works fine, MY_TABLE_ID starts with 1 and works as expected.
My issue is, If somebody inserts data manually before I do my POST then I get duplicate key exception as myTableId is entered as 1 which is already present.
My main problem is I can't create database sequence for using GenerationType.SEQUENCE now to resolve this as database can't be altered now.
I have tried various combinations of GenerationType, TableGenerator but I am unable to successfully tackle it.
Setting initialValue to some larger number to avoid duplicate values can temporarily resolve my problem but I am unable to do it too.
If someone can help me with initialValue with AUTO or give me some other better solution without database changes will be great :)
As MY_TABLE_ID is an identity column, following annotations will work.
#Entity
#Table(name = "MY_TABLE")
public class MyEntity {
#Id
#GeneratedValue(strategy=GenerationType.IDENTITY) // <-- IDENTITY instead of AUTO
#Column(name = "MY_TABLE_ID")
private Integer myTableId;
#Column(name = "MY_TABLE_NM")
private String myTableName;
//Getters Setters
}
The identity column will automatically assign an value as soon as the transaction is committed. You are not to set any values for an identity column, as its the job of the database to assign the values. Therefore you also don't need to think about any initial values (forget them completely for identity columns)
I tried various options in answers provided here and for similar questions on stackoverflow and other forums,
I had few limitations,
I couldn't create database sequence as my database changes were freezed.
I didn't want to introduce new Custom IdGenerator class because it would add confusion to other people working with me.
It was resolved using following change:
Adding GenericGenerator with increment strategy helped me, I made following changes to my code.
#Entity
#Table(name = "MY_TABLE")
public class MyEntity {
#Id
#GeneratedValue(strategy = GenerationType.AUTO, generator="seq")
#GenericGenerator(name = "seq", strategy="increment")
#Column(name = "MY_TABLE_ID")
private Integer myTableId;
#Column(name = "MY_TABLE_NM")
private String myTableName;
//Getters Setters
}
It helped me because,
From Hiberbate DOCs
increment
An IdentifierGenerator that returns a long, constructed by counting
from the maximum primary key value at startup. Not safe for use in a
cluster!
Since, it was incrementing already existing myTableId even if it was manually inserted, this resolved my issue.
You can also implement your own generator if you need more control.
See this interface IdentifierGenerator.
So you can get the count of records, for example through a #NamedQuery.
Then you can generate an identifier yourself.
public class MyEntityKeyGenerator implements IdentifierGenerator {
#Override
public Serializable generate(SessionImplementor session, Object object) {
// SELECT count(ent) from MyEntity ent;
Long count = (Long) session.getNamedQuery("count-query").uniqueResult();
// calc and return id value
}
}
Entity:
class MyEntity {
#Id
#GenericGenerator(name = "my_generator",
strategy = "org.common.MyEntityKeyGenerator")
#GeneratedValue(generator = "my_generator")
private Long id;...
Just do not forget about the lock.
I use the generation type Identity, which basically means that the db, takes care of Id generation.
#AllArgsConstructor
#NoArgsConstructor
#Getter
#Setter
#MappedSuperclass
#EntityListeners(EntityListener.class)
#EqualsAndHashCode(of = {"id", "createdAt"})
public abstract class AbstractEntity<ID extends Serializable> implements Serializable {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private ID id;
#Temporal(TemporalType.TIMESTAMP)
#Column(name = "CREATED_AT", updatable = false)
private Date createdAt;
#Temporal(TemporalType.TIMESTAMP)
#Column(name = "UPDATED_AT")
private Date updatedAt;
}
You can also use, Sequence generation:
#Entity
#SequenceGenerator(name="seq", initialValue=1, allocationSize=100)
public class EntityWithSequenceId {
#GeneratedValue(strategy=GenerationType.SEQUENCE, generator="seq")
#Id long id;
}
I have developed a REST- API with Spring Web and Hibernate.
I deployed it in two server instances and it runs without any problem for about 5 months. Now it is mostly working but in some periods "MySQLIntegrityConstraintViolationException" with message "Duplicate entry '235648' for key 'PRIMARY'" are thrown (te duplicate id is changing in the exceptions).
The class, for which the exception is thrown, looks like this:
#Entity
#Table(name = "Metadata", catalog = "data")
public class Metadata{
private Long id;
private String field1;
private String field2;
//...
#Id
#Column(unique = true, nullable = false)
#GeneratedValue(strategy = GenerationType.TABLE)
public Long getId() {
return id;
}
//More Getters and Setters...
}
There was neither change to java code nor changes on the MySql-database.
Do you have any idea why it stopped working properly?
Most likely, the number of requests which end up creating entities which use that table for id generation has increased.
One of the remedies would be to catch that exception in a parent method and retry (probably this would be some kind of PessimisticLock exception as the id table has to be physically locked while retrieving and updating its content).
Another one would be to increase the allocationSize option, which for you is 50 being the default if no custom set-up is done. You would need to reenter the hibernate default table / columns names as this has been already created in the database:
#Id
#Column(unique = true, nullable = false)
#TableGenerator(
name="tableGen",
table="hibernate_sequences",
pkColumnName="sequence_name",
valueColumnName="next_val",
pkColumnValue="default",
allocationSize=100
#GeneratedValue(strategy = GenerationType.TABLE, generator="tableGen")
public Long getId() {
return id;
}
Here is a nice post which explains the scalability pitfalls of a TABLE generation strategy -> link
#GeneratedValue(strategy = GenerationType.IDENTITY)
worked for me.
My entity has a mapOrder field which I want auto-increment like below:
#Entity
public class Map{
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
#Column(columnDefinition = "serial")
private Long mapOrder;
//.......
}
The sql generated seems good:
CREATE TABLE map
(
id bigserial NOT NULL,
map_order serial NOT NULL,
...
)
But when I save it with Spring Data JPA's repository, like this:
Map m=new Map();
repo.save(m);
will give me exception:
Caused by: org.postgresql.util.PSQLException: ERROR: null value in column "map_order" violates not-null constraint
Any ideas?
Try changing your code to this:
#GeneratedValue(strategy = GenerationType.SEQUENCE)
Reference: https://stackoverflow.com/a/29028369
#GeneratedValue works with identifiers and you can't use it with regular fields.
You can, for example, use some object for sequences (with any key generation strategy):
#Entity
public class JpaNoPkSequence {
#Id
#GeneratedValue(strategy=GenerationType.AUTO)
#Column(name="id", nullable=false, updatable=false)
private Long id;
}
For using the strategy GenerationType.SEQUENCE the sequence should be created in the database:
CREATE SEQUENCE JPA_PK_SEQ START WITH 1 INCREMENT BY 1 NOCACHE NOCYCLE;
ALTER SEQUENCE "JPA_PK_SEQ" OWNER TO something;
This should be specified in the key definition. You should also add a one-to-one relationship with the object that you will use to obtain sequences for regular fields:
#Entity
public class Map {
#Id
#SequenceGenerator(name="jpaPkSeq", sequenceName="JPA_PK_SEQ", allocationSize=1, initialValue = 1)
#GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "jpaPkSeq")
#Column(name = "id", nullable=false, updatable=false)
private Long id;
#OneToOne
private JpaNoPkSequence sequence;
...
}
Hope this helps.
I had the same problem. In my case, the error was in creating the table.
You need to use SERIAL type instead of others (at least in Postgres).
Before (bigint type)
CREATE TABLE IF NOT EXISTS sample_table
(
id BIGINT NOT NULL,
...
);
After (serial type)
CREATE TABLE IF NOT EXISTS sample_table
(
id SERIAL NOT NULL,
...
);
The id in the entity class looked like this:
#Id
#GeneratedValue(strategy = IDENTITY)
private Long id;
This question is full of bad advice. The problem is the second column with a serial value. The problem is that Hibernate explicitly inserts a null there. You have to tell it not to.
#Column(columnDefinition = "serial", insertable = false)
private Long mapOrder;
I am using hibernate annotations. I want to make a column as autoincremented. I have created a sequence in database(oracle) and mapped that sequence in java POJO class. Do I need to create trigger for that sequence too? I want to know how we can make a column autoincremented while using hibernate anotation? What changes i have to do in java and as well as database side? Please help me in this. Following is the part of code where I have mapped the sequence.
public class SimRuns implements Serializable {
private static final long serialVersionUID = 8698324570356602407L;
#Id #Column(name = "RUN_ID")
#GeneratedValue(strategy=GenerationType.SEQUENCE, generator="seq_run_id")
#SequenceGenerator(name="seq_run_id", sequenceName="seq_run_id")
private Long runId;
}
This works for me:
#Id
#GeneratedValue(generator = "nosicSeq")
#SequenceGenerator(name = "nosicSeq", sequenceName = "NOSIC_SEQ", allocationSize = 1)
#Column(name = "SID")
private BigDecimal sid;
no triggers in DB needed, just sequence.
Try removing the generator and setting to auto the generationType
#Id #Column(name = "RUN_ID")
#GeneratedValue(strategy=GenerationType.AUTO)
#SequenceGenerator(name="seq_run_id", sequenceName="seq_run_id")
private Long runId;
Hibernate is probably the only JPA Provider that selects the right Generationstrategy based on your databasetype. Using the GenerationType.AUTO statement hibernate will try to select the best strategy to implement an increasing row id.
In Oracle : It's no need for an Oracle trigger, but the sequence is must.
In pojo: you can use Annotations like this:
#Id
#GeneratedValue(strategy=GenerationType.SEQUENCE, generator="majorsSeq")
#SequenceGenerator(name="majorsSeq", sequenceName="MAJORS_SEQ", allocationSize = 1,initialValue = 1)
public int getId() {
return id;
}