How to fix the Hibernate object references an unsaved transient instance - save the transient instance before flushing error

Question

I receive following error when I save the object using Hibernate   object references an unsaved transient instance - save the transient instance before flushing

User · Answer

This issue happened to me when I created a new entity and an associated entity in a method marked as @Transactional, then performed a query before saving. Ex

@Transactional
public someService() {
    Entity someEntity = new Entity();
    AssocaiatedEntity associatedEntity = new AssocaitedEntity();
    someEntity.setAssociatedEntity(associatedEntity);
    associatedEntity.setEntity(someEntity);

    // Performing any query was causing hibernate to attempt to persist the new entity. It would then throw an exception
    someDao.getSomething();

    entityDao.create(someEntity);
}

To fix, I performed the query before creating the new entity.

User · Answer

If you re using Spring Data JPA then addition  Transactional annotation to your service implementation would solve the issue

User · Answer

It can also happen when you are having OneToMany relation and you try to add the child entity to the list in parent entity  then retrieve this list through parent entity  before saving this parent entity   without saving child entity itself  e g   Child childEntity   new Child    parentEntity addChild childEntity   parentEntity getChildren       I needed the retrieval for logging  but one may need it for other reasons  parentRepository save parentEntity    The error was thrown when I saved the parent entity  If I removed the retrieval in the previous row  then the error was not thrown  but of course that s not the solution  The solution was saving the childEntity and adding that saved child entity to the parent entity  like this  Child childEntity   new Child    Child savedChildEntity   childRepository save childEntity   parentEntity addChild savedChildEntity   parentEntity getChildren    parentRepository save parentEntity

User · Answer

Introduction When using JPA and Hibernate  an entity can be in one of the following 4 states   New - A newly created object that hasn   t ever been associated with a Hibernate Session  a k a Persistence Context  and is not mapped to any database table row is considered to be in the New or Transient state   To become persisted we need to either explicitly call the persist method or make use of the transitive persistence mechanism   Persistent - A persistent entity has been associated with a database table row and it   s being managed by the currently running Persistence Context   Any change made to such an entity is going to be detected and propagated to the database  during the Session flush-time    Detached - Once the currently running Persistence Context is closed all the previously managed entities become detached  Successive changes will no longer be tracked and no automatic database synchronization is going to happen   Removed - Although JPA demands that managed entities only are allowed to be removed  Hibernate can also delete detached entities  but only through a remove method call     Entity state transitions To move an entity from one state to the other  you can use the persist  remove or merge methods   Fixing the problem The issue you are describing in your question  object references an unsaved transient instance - save the transient instance before flushing  is caused by associating an entity in the state of  New to an entity that s in the state of Managed  This can happen when you are associating a child entity to a one-to-many collection in the parent entity  and the collection does not cascade the entity state transitions  So  you can fix this by adding cascade to the entity association that triggered this failure  as follows  The  OneToOne association  OneToOne      mappedBy    quot post quot       orphanRemoval   true      cascade   CascadeType ALL  private PostDetails details    Notice the CascadeType ALL value we added for the cascade attribute   The  OneToMany association  OneToMany      mappedBy    quot post quot        orphanRemoval   true      cascade   CascadeType ALL  private List lt Comment gt  comments   new ArrayList lt  gt      Again  the CascadeType ALL is suitable for the bidirectional  OneToMany associations  Now  in order for the cascade to work properly in a bidirectional  you also need to make sure that the parent and child associations are in sync  The  ManyToMany association  ManyToMany      mappedBy    quot authors quot       cascade             CascadeType PERSIST           CascadeType MERGE         private List lt Book gt  books   new ArrayList lt  gt      In a  ManyToMany association  you cannot use CascadeType ALL or orphanRemoval as this will propagate the delete entity state transition from one parent to another parent entity  Therefore  for  ManyToMany associations  you usually cascade the CascadeType PERSIST or CascadeType MERGE operations  Alternatively  you can expand that to DETACH or REFRESH

User · Answer

I also faced the same situation  By setting following annotation above the property made it solve the exception prompted   The Exception I faced   Exception in thread  main  java lang IllegalStateException  org hibernate TransientObjectException  object references an unsaved transient instance - save the transient instance before flushing  com model Car OneToMany   To overcome  the annotation I used        OneToMany cascade    CascadeType ALL        Column name    ListOfCarsDrivenByDriver       private List lt Car OneToMany gt  listOfCarsBeingDriven   new ArrayList lt Car OneToMany gt       What made Hibernate throw the exception   This exception is thrown at your console because the child object I attach to the parent object is not present in the database at that moment   By providing  OneToMany cascade    CascadeType ALL     it tells Hibernate to save them to the database while saving the parent object

User · Answer

You should include cascade  all   if using xml  or cascade CascadeType ALL  if using annotations  on your collection mapping   This happens because you have a collection in your entity  and that collection has one or more items which are not present in the database  By specifying the above options you tell hibernate to save them to the database when saving their parent

User · Answer

In my case using Cascade ALL was adding unnecessary entry to the table  which already had same object  Generating a child value without an id does just that   So I would have to work around with getting child object from repository first  and setting it into the main object instead of the one causing the issue  Student s   studentRepo findByName generatedObject getStudent   getName    generatedObject student s

User · Answer

Or  if you want to use minimal  powers   e g  if you don t want a cascade delete  to achieve what you want  use   import org hibernate annotations Cascade  import org hibernate annotations CascadeType         Cascade  CascadeType SAVE UPDATE   private Set lt Child gt  children

User · Answer

Case 1  I was getting this exception when I was trying to create a parent and saving that parent reference to its child and then some other DELETE UPDATE query JPQL   So I just flush   the newly created entity after creating parent and after creating child using same parent reference  It Worked for me   Case 2    Parent class  public class Reference implements Serializable         Id      Column precision 20  scale 0      private BigInteger id        Temporal TemporalType TIMESTAMP      private Date modifiedOn        OneToOne mappedBy  reference       private ReferenceAdditionalDetails refAddDetails                         Child Class   public class ReferenceAdditionalDetails implements Serializable       private static final long serialVersionUID   1L        Id      OneToOne      JoinColumn name  reference  referencedColumnName  id       private Reference reference       private String preferedSector1      private String preferedSector2                   In the above case where parent Reference  and child ReferenceAdditionalDetails  having OneToOne relationship and when you try to create Reference entity and then its child ReferenceAdditionalDetails   it will give you the same exception  So to avoid the exception you have to set null for child class and then create the parent  Sample Code       reference setRefAddDetails null   reference   referenceDao create reference   entityManager flush

User · Answer

I was facing the same error for all PUT HTTP transactions  after introducing optimistic locking   Version  At the time of updating an entity it is mandatory to send id and version of that entity  If any of the entity fields are related to other entities then for that field also we should provide id and version values  without that the JPA try to persist that related entity first as a new entity Example  we have two entities -- gt  Vehicle id Car version    Car id  version  brand   to update persist Vehicle entity make sure the Car field in vehicle entity has id and version fields provided

User · Answer

I believe this might be just repeat answer  but just to clarify  I got this on a  OneToOne mapping as well as a  OneToMany   In both cases  it was the fact that the Child object I was adding to the Parent wasn t saved in the database yet   So when I added the Child to the Parent  then saved the Parent  Hibernate would toss the  object references an unsaved transient instance - save the transient instance before flushing  message when saving the Parent   Adding in the cascade    CascadeType ALL  on the Parent s reference to the Child solved the problem in both cases   This saved the Child and the Parent   Sorry for any repeat answers  just wanted to further clarify for folks    OneToOne cascade    CascadeType ALL    JoinColumn name    performancelog id   public PerformanceLog getPerformanceLog         return performanceLog

User · Answer

Simple way of solving this issue is save the both entity  first save the child entity and then save the parent  entity  Because parent entity is depend on child entity for the foreign key value   Below simple exam of one to one relationship  insert into Department  name  numOfemp  Depno  values           Hibernate  insert into Employee  SSN  dep Depno  firstName  lastName  middleName  empno  values                     Session session sf openSession            session beginTransaction            session save dep           session save emp

User · Answer

i get this error when i use   getSession   save object    but it works with no problem when I use   getSession   saveOrUpdate object

User · Answer

If your collection is nullable just try  object SetYouColection null

User · Answer

I faced this exception when I  did not persist parent object but I was saving the child  To resolve the issue  with in the same session I persisted both the child and parent objects and used  CascadeType ALL on the parent

User · Answer

This happens when saving an object when Hibernate thinks it needs to save an object that is associated with the one you are saving    I had this problem and did not want to save changes to the referenced object so I wanted the cascade type to be NONE    The trick is to ensure that the ID and VERSION in the referenced object is set so that Hibernate does not think that the referenced object is a new object that needs saving  This worked for me   Look through all of the relationships in the class you are saving to work out the associated objects  and the associated objects of the associated objects  and ensure that the ID and VERSION is set in all objects of the object tree

User · Answer

There are so many possibilities of this error some other possibilities are   also on add page or edit page  In my case I was trying to save a object AdvanceSalary  The problem is that in edit the AdvanceSalary employee employee id is null Because on edit I was not set the employee employee id  I have make a hidden field and set it  my code working absolutely fine        Entity name    ic advance salary        Table name    ic advance salary       public class AdvanceSalary extends BaseDO            Id          GeneratedValue strategy   GenerationType IDENTITY           Column name    id           private Integer id            ManyToOne fetch   FetchType EAGER           JoinColumn name    employee id   nullable   false          private Employee employee            Column name    employee id   insertable false  updatable false           NotNull message  Please enter employee Id           private Long employee id            Column name    advance date            DateTimeFormat pattern    dd-MMM-yyyy            NotNull message  Please enter advance date           private Date advance date            Column name    amount            NotNull message  Please enter Paid Amount           private Double amount            Column name    cheque date            DateTimeFormat pattern    dd-MMM-yyyy           private Date cheque date            Column name    cheque no           private String cheque no            Column name    remarks           private String remarks           public AdvanceSalary                        public AdvanceSalary Integer advance salary id                this id   advance salary id                     public Integer getId                 return id                     public void setId Integer id                this id   id                     public Employee getEmployee                 return employee                     public void setEmployee Employee employee                this employee   employee                      public Long getEmployee id                 return employee id                     public void setEmployee id Long employee id                this employee id   employee id

User · Answer

Just make Constructor of your mapping in your base class  Like if you want One-To-One relation in Entity A  Entity B  if your are taking A as base class  then A must have a Constructor have B as a argument

User · Answer

This isn t the only reason for the error  I encountered it just now for a typo error in my coding  which I believe  set a value of an entity which was already saved   X x2   new X    x setXid memberid      Error happened here - x was a previous global entity I created earlier Y setX x2     I spotted the error by finding exactly which variable caused the error  in this case String xid   I used a catch around the whole block of code that saved the entity and printed the traces        code block that performed the operation   catch  Exception e       e printStackTrace       put a break-point here and inspect the  e     return ERROR

User · Answer

There is another possibility that can cause this error in hibernate  You may set an unsaved reference of your object A to an attached entity B and want to persist object C  Even in this case  you will get the aforementioned error

User · Answer

To add my 2 cents  I got this same issue when I m accidentally sending null as the ID  Below code depicts my scenario  and OP didn t mention any specific scenario    Employee emp   new Employee    emp setDept new Dept deptId       -- gt  when deptId PKID is null  same error will be thrown    calls to other setters    em persist emp     Here I m setting the existing department id to a new employee instance without actually getting the department entity first  as I don t want to another select query to fire   In some scenarios  deptId PKID is coming as null from calling method and I m getting the same error    So  watch for null values for PK ID

User · Answer

I think is because you have try to persist an object that have a reference to another object that is not persist yet  and so it try in the  DB side  to put a reference to a row that not exists

User · Answer

Don t use Cascade All until you really have to  Role and Permission have bidirectional manyToMany relation  Then the following code would work fine        Permission p   new Permission        p setName  help        Permission p2   new Permission        p2 setName  self info        p    Permission crudRepository save p      returned p has id filled in      p2    Permission crudRepository save p2      so does p2      Role role   new Role        role setAvailable true       role setDescription  a test role        role setRole  admin        List lt Permission gt  pList   new ArrayList lt Permission gt         pList add p       pList add p2       role setPermissions pList       crudRepository save role     while if the object is just a  new  one  then it would throw the same error

User · Answer

One possible cause of the error is the inexistence of the setting of the value of the parent entity   for example for a department-employees relationship you have to write this in order to fix the error    Department dept    Department session load Department class  dept code      dept code is from the jsp form which you get in the controller with  RequestParam String department employee setDepartment dept

User · Answer

My problem was related to  BeforeEach of JUnit  And even if I saved the related entities  in my case  ManyToOne   I got the same error   The problem is somehow related to the sequence that I have in my parent  If I assign the value to that attribute  the problem is solved   Ex  If I have the entity Question that can have some categories  one or more  and entity Question has a sequence    GeneratedValue strategy   GenerationType SEQUENCE  generator    feedbackSeq    Id private Long id    I have to assign the value question setId 1L

User · Answer

In my case   issue was completely different  I have two classes let s say c1  amp  c2  Between C1  amp  C2 dependency is OneToMany  Now if i am saving C1 in DB it was throwing above error  Resolution of this problem was to get first C2 s id from consumer request and find C2 via repository call Afterwards save c2 into C1 object  Now if i am saving C1  it s working fine

User · Answer

For the sake of completeness  A  org hibernate TransientPropertyValueException    with message  object references an unsaved transient instance - save the transient instance before flushing   will also occur when you try to persist   merge an entity with a reference to another entity which happens to be detached

User · Answer

In my case it was caused by not having CascadeType on the  ManyToOne side of the bidirectional relationship  To be more precise  I had CascadeType ALL on  OneToMany side and did not have it on  ManyToOne  Adding CascadeType ALL to  ManyToOne resolved the issue  One-to-many side    OneToMany cascade   CascadeType ALL  mappedBy  globalConfig   orphanRemoval   true  private Set lt GlobalConfigScope gt gcScopeSet    Many-to-one side  caused the problem    ManyToOne  JoinColumn name  global config id   private GlobalConfig globalConfig    Many-to-one  fixed by adding CascadeType PERSIST    ManyToOne cascade   CascadeType PERSIST   JoinColumn name  global config id   private GlobalConfig globalConfig

User · Answer

One other possible reason  in my case  I was attempting to save the child before saving the parent  on a brand new entity   The code was something like this in a User java model   this lastName   lastName  this isAdmin   isAdmin  this accountStatus    Active   this setNewPassword password   this timeJoin   new Date    create      The setNewPassword   method creates a PasswordHistory record and adds it to the history collection in User  Since the create   statement hadn t been executed yet for the parent  it was trying to save to a collection of an entity that hadn t yet been created  All I had to do to fix it was to move the setNewPassword   call after the call to create     this lastName   lastName  this isAdmin   isAdmin  this accountStatus    Active   this timeJoin   new Date    create    this setNewPassword password

User · Answer

beside all other good answers  this could happen if you use merge to persist an object and accidentally forget to use merged reference of the object in the parent class  consider the following example  merge A   B setA A   persist B     In this case  you merge A but forget to use merged object of A  to solve the problem you must rewrite the code like this   A merge A    difference is here B setA A   persist B

User · Answer

This occurred for me when persisting an entity in which the existing record in the database had a NULL value for the field annotated with  Version  for optimistic locking   Updating the NULL value to 0 in the database corrected this

[java] How to fix the Hibernate "object references an unsaved transient instance - save the transient instance before flushing" error

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