How to set a default entity property value with Hibernate

Question

How do I set a default value in Hibernate field

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use hibernate annotation   ColumnDefault  -1   private Long clientId

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If you want a real database default value  use columnDefinition    Column name    myColumn   nullable   false  columnDefinition    int default 100      Notice that the string in columnDefinition is database dependent  Also if you choose this option  you have to use dynamic-insert  so Hibernate doesn t include columns with null values on insert  Otherwise talking about default is irrelevant   But if you don t want database default value  but simply a default value in your Java code  just initialize your variable like that - private Integer myColumn   100

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If you want to do it in database   Set the default value in database  sql server sample    ALTER TABLE  TABLE NAME  ADD  CONSTRAINT  CONSTRAINT NAME   DEFAULT  newid    FOR  COLUMN NAME    Mapping hibernate file        lt hibernate-mapping                       lt property name  fieldName  column  columnName  type  Guid  access  field  not-null  false   insert  false  update  false     gt            See  the key is insert  false  update  false

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You can use the java class constructor to set the default values  For example   public class Entity implements Serializable   private Double field1  private Integer field2   private T fieldN    public Entity      this field1 0 0    this field2 0          this fieldN   lt your default value gt         Setters and Getters

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Suppose we have an entity which contains a sub-entity  Using insertable   false  updatable   false on the entity prevents the entity from creating new sub-entities and preceding the default DBMS value  But the problem with this is that we are obliged to always use the default value or if we need the entity to contain another sub-entity that is not the default  we must try to change these annotations at runtime to insertable   true  updatable   true  so it doesn t seem like a good path  Inside the sub-entity if it makes more sense to use in all the columns insertable   false  updatable   false so that no more sub-entities are created regardless of the method we use  with  DynamicInsert it would not be necessary  Inserting a default value can be done in various ways such as Default entity property value using constructor or setter  Other ways like using JPA with columnDefinition have the drawback that they insert a null by default and the default value of the DBMS does not precede   Insert default value using DBMS and optional using Hibernate But using  DynamicInsert we avoid sending a null to the db when we want to insert a sub-entity with its default value  and in turn we allow sub-entities with values other than the default to be inserted   For inserting  should this entity use dynamic sql generation where only non-null columns get referenced in the prepared sql statement   Given the following needs   The entity does not have the responsibility of creating new sub-entities  When inserting an entity  the sub-entity is the one that was defined as default in the DBMS  Possibility of creating an entity with a sub-entity which has a UUID other than the default   DBMS  PostgreSQL   Language  Kotlin  Entity  Table name    quot entity quot    DynamicInsert data class EntityTest           Id  GeneratedValue  Column name    quot entity uuid quot   val entityUUID  UUID    null            OneToOne cascade    CascadeType ALL            JoinColumn name    quot subentity uuid quot   referencedColumnName    quot subentity uuid quot           var subentityTest  SubentityTest    null        Entity  Table name    quot subentity quot   data class SubentityTest           Id  GeneratedValue  Column name    quot subentity uuid quot   insertable   false  updatable   false  var subentityUUID  UUID    null           Column insertable   false  updatable   false  var name  String              constructor     this name    quot  quot      And the value is set by default in the database  alter table entity alter column subentity uuid set default  d87ee95b-06f1-52ab-83ed-5d882ae400e6   uuid   GL  Source 1 Source 2

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lt property name  age  type  integer  gt   lt column name  age  not-null  false  default  null    gt   lt  property gt

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If you want to set default value in terms of database  just set  Column  columnDefinition    int default 1    But if what you intend is to set a default value in your java app you can set it on your class attribute like this  private Integer attribute   1

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Default entity property value If you want to set a default entity property value  then you can initialize the entity field using the default value  For instance  you can set the default createdOn entity attribute to the current time  like this   Column      name    quot created on quot    private LocalDateTime createdOn   LocalDateTime now     Default column value using JPA If you are generating the DDL schema with JPA and Hibernate  although this is not recommended  you can use the columnDefinition attribute of the JPA  Column annotation  like this   Column      name    quot created on quot        columnDefinition    quot DATETIME 6  DEFAULT CURRENT TIMESTAMP quot     Generated GenerationTime INSERT  private LocalDateTime createdOn   The  Generated annotation is needed because we want to instruct Hibernate to reload the entity after the Persistence Context is flushed  otherwise  the database-generated value will not be synchronized with the in-memory entity state  Instead of using the columnDefinition  you are better off using a tool like Flyway and use DDL incremental migration scripts  That way  you will set the DEFAULT SQL clause in a script  rather than in a JPA annotation  Default column value using Hibernate If you are using JPA with Hibernate  then you can also use the  ColumnDefault annotation  like this   Column name    quot created on quot    ColumnDefault value  quot CURRENT TIMESTAMP quot    Generated GenerationTime INSERT  private LocalDateTime createdOn   Default Date Time column value using Hibernate If you are using JPA with Hibernate and want to set the creation timestamp  then you can use the  CreationTimestamp annotation  like this   Column name    quot created on quot    CreationTimestamp private LocalDateTime createdOn

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You can use  PrePersist anotation and set the default value in pre-persist stage   Something like that         some code private String myProperty        some code   PrePersist public void prePersist         if myProperty    null    We set default value in case if the value is not set yet          myProperty    Default value         property methods  Column nullable   false    restricting Null value on database level  public String getMyProperty         return myProperty     public void setMyProperty String myProperty        this myProperty  myProperty      This method is not depend on database type version underneath the Hibernate  Default value is set before persisting the mapping object

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what about just setting a default value for the field   private String  foo    default      property here public String Foo   if they pass a value  then it will be overwritten  otherwise  you have a default

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Working with Oracle  I was trying to insert a default value for an Enum  I found the following to work the best    Column nullable   false   Enumerated EnumType STRING  private EnumType myProperty   EnumType DEFAULT VALUE

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i am working with hibernate 5 and postgres  and this worked form me     Column name    ACCOUNT TYPE      nullable    false  columnDefinition  varchar2 default  END USER     Enumerated EnumType STRING  private AccountType accountType

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I searched for this and found many answers to default value for column If you want to use default value defined in SQL Table then in  Column Annotation use  insertable   false   insertable       Column name   columnName  length   lengthOfColumn  insertable   false    If you are using columnDefination it  Column annotation may be it won t work as it is Database dependent

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One solution is to have your getter check to see if whatever value you are working with is null  or whatever its non-initialized state would be  and if it s equal to that  just return your default value   public String getStringValue         return  this stringValue    null     Default    stringValue

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To use default value from any column of table  then you must need to define  DynamicInsert as true or else you just define  DynamicInsert  Because hibernate takes by default as a true   Consider as the given example    AllArgsConstructor  Table name    core contact    DynamicInsert public class Contact implements Serializable         Column name    status   columnDefinition    int default 100       private Long status

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Use  ColumnDefault   annotation  This is hibernate only though

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The above suggestion works  but only if the annotation is used on the getter method  If the annotations is used where the member is declared  nothing will happen   public String getStringValue         return  this stringValue    null     Default    stringValue

[java] How to set a default entity property value with Hibernate

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