Internal Website Search

Fields of persistable user defined classes (entity classes, embeddable classes and mapped superclasses) can be classified into the following five groups: Transient fields Persistent fields Inverse (Mapped By) fields Primary key (ID) fields Version field The first three groups (transient

The way a field of a persistable class is managed by JPA can be set by the following annotations: Additional annotations (and enum) are designated for enum fields : Other additional annotations (and enum) are designated for date and calendar fields : Chapter 2 of the ObjectDB manual explains how to use all the above annotations.

but all its other persistent fields are uninitialized. The object content is retrieved from the database and the persistent fields are initialized, lazily, when the entity object is first accessed ... collection and map persistent fields (i.e. through one-to-one and many-to-one relationships

and embeddable classes) in the database and their persistent fields and indexes. The [Query] window enables ... a single object, every column represents a persistent field , and the content of a cell is the value of a single field in a single database object. This type of viewer is useful for viewing data of a simple

Modifications to entity classes that do not change their persistent field definitions ... and non persistent fields . However, additions, deletions and modifications to the persistent fields ... again. Conversion of an entity object to the new schema is done on a field by field basis: For every field

which fields to define with indexes should be done carefully. Single Field Index The following entity ... ; cannot be applied to fields ): import javax.jdo.annotations.Index; import javax.jdo.annotations.Unique ... that prevents duplicate values in the indexed field . A PersistenceException is thrown on commit (or flush

a primary key field : @Entity public class Project { @Id @GeneratedValue long id; // still set automatically : } The @Id annotation marks a field as a primary key field . When a primary key field is defined the primary key value is automatically injected into that field by ObjectDB. The 

queries with the same arguments). Many other internal caches. Indexing Single field and multi field ...  and type versioning. Class hierarchy changes are handled automatically. New added fields are handled automatically. Removed fields are handled automatically. Most field type changes are handled

can be stored in the database directly. Other persistable types can be embedded in entity classes as fields ... multiple persistent fields  would cause data duplication in the database. Entity Classes An entity ... . It can contain constructors, methods, fields and nested types with any access modifiers (public, protected

; @Entity public class Point { // Persistent Fields : private int x; private int y; // Constructor: Point ... (except that all JPA exceptions are unchecked whereas Java IO exceptions are checked). Persistent Fields in ... . Only the persistent state of the entity object, as reflected by its persistent fields  is stored. By default

). Retrieval by navigation from detached objects is not supported, so only persistent fields ... . Cascading Detach Marking a reference field with CascadeType . DETACH (or CascadeType ... objects that are referenced by that field (multiple entity objects can be referenced by a collection

Marking a field with the @GeneratedValue annotation specifies that a value will be automatically generated for that field . This is primarily intended for primary key fields but ObjectDB also supports this annotation for non-key numeric persistent fields as well. Several different value generation

details on managed classes and persistent fields and properties, similarly to the ability ... (); The ManagedType  interface adds methods for exploring managed fields and properties (which are referred ... an ID class when using multiple ID fields or properties. Finally, the EntityType interface adds

The way a field of a persistable class is managed by JDO can be set by the following annotations and enum types:

that case the fields of class X are not persistent fields , and when an instance of class C is stored, only persistent fields from classes B and C are stored. The closest persistent super class in ... ;Metadata for Fields Unlike persistent classes, which must be listed in the JDO metadata, persistent

. It can include constructors, methods, fields , attributes ( final , abstract , public ), inheritance ... (constructors, methods and fields ) can have any access modifiers (i.e. public, protected, package or private). 3.2  Persistent Fields and Types Storing a persistent object in the database does not

from the list of classes at the top of this window and see all its persistent fields ... represents a persistent field , and the content of a cell is the value of a single field in a single ... a tree node, and the values of its persistent fields are represents by child nodes. The main advantage

. The execute() method compiles and runs the query. If there is no age field in class Person or if the field exists but its type cannot be compared with an int value, a JDOUserException is thrown ... are included in the result collection. If an index is defined for the age field (see section 4.5

, every transient object that, at commit time, is reachable from a persistent object (using persistent fields ... that are reachable from it can be retrieved simply by navigating through the persistent fields ... the database (in whatever manner) all its persistent fields can be accessed freely. This includes fields

;pc,    int  field ,    double currentValue,    double newValue ) Mark the field as modified by the user. Parameters: pc - the calling PersistenceCapable instance field - the field number currentValue - the current value of the field newValue - the proposed new value of the field Since: JDO 1.0

;pc,    int  field ,    float currentValue,    float newValue ) Mark the field as modified by the user. Parameters: pc - the calling PersistenceCapable instance field - the field number currentValue - the current value of the field newValue - the proposed new value of the field Since: JDO 1.0

;pc,    int  field ,    Object currentValue,    Object newValue ) Mark the field as modified by the user. Parameters: pc - the calling PersistenceCapable instance field - the field number currentValue - the current value of the field newValue - the proposed new value of the field Since: JDO 1.0

;pc,    int  field ,    String currentValue,    String newValue ) Mark the field as modified by the user. Parameters: pc - the calling PersistenceCapable instance field - the field number currentValue - the current value of the field newValue - the proposed new value of the field Since: JDO 1.0

;pc,    int  field ,    short currentValue,    short newValue ) Mark the field as modified by the user. Parameters: pc - the calling PersistenceCapable instance field - the field number currentValue - the current value of the field newValue - the proposed new value of the field Since: JDO 1.0

;pc,    int  field ,    byte currentValue,    byte newValue ) Mark the field as modified by the user. Parameters: pc - the calling PersistenceCapable instance field - the field number currentValue - the current value of the field newValue - the proposed new value of the field Since: JDO 1.0

;pc,    int  field ,    long currentValue,    long newValue ) Mark the field as modified by the user. Parameters: pc - the calling PersistenceCapable instance field - the field number currentValue - the current value of the field newValue - the proposed new value of the field Since: JDO 1.0

,    int  field ,    int currentValue,    int newValue ) Mark the field as modified by the user. Parameters: pc - the calling PersistenceCapable instance field - the field number currentValue - the current value of the field newValue - the proposed new value of the field Since: JDO 1.0

;pc,    int  field ,    char currentValue,    char newValue ) Mark the field as modified by the user. Parameters: pc - the calling PersistenceCapable instance field - the field number currentValue - the current value of the field newValue - the proposed new value of the field Since: JDO 1.0

 pc,    int  field ,    String currentValue ) Return the value for the field . Parameters: pc - the calling PersistenceCapable instance field - the field number currentValue - the current value of the field Return: the new value for the field Since: JDO 1.0

 pc,    int  field ,    double currentValue ) Return the value for the field . Parameters: pc - the calling PersistenceCapable instance field - the field number currentValue - the current value of the field Return: the new value for the field Since: JDO 1.0

 pc,    int  field ,    boolean currentValue,    boolean newValue ) Mark the field as modified by the user. Parameters: pc - the calling PersistenceCapable instance field - the field number currentValue - the current value of the field

 pc,    int  field ,    Object currentValue ) Return the value for the field . Parameters: pc - the calling PersistenceCapable instance field - the field number currentValue - the current value of the field Return: the new value for the field Since: JDO 1.0

,    int  field ,    int currentValue ) Return the value for the field . Parameters: pc - the calling PersistenceCapable instance field - the field number currentValue - the current value of the field Return: the new value for the field Since: JDO 1.0

;pc,    int  field ,    short currentValue ) Return the value for the field . Parameters: pc - the calling PersistenceCapable instance field - the field number currentValue - the current value of the field Return: the new value for the field Since: JDO 1.0

;pc,    int  field ,    float currentValue ) Return the value for the field . Parameters: pc - the calling PersistenceCapable instance field - the field number currentValue - the current value of the field Return: the new value for the field Since: JDO 1.0

;pc,    int  field ,    long currentValue ) Return the value for the field . Parameters: pc - the calling PersistenceCapable instance field - the field number currentValue - the current value of the field Return: the new value for the field Since: JDO 1.0

 pc,    int  field ,    boolean currentValue ) Return the value for the field . Parameters: pc - the calling PersistenceCapable instance field - the field number currentValue - the current value of the field Return: the new value for the field Since: JDO 1.0

;pc,    int  field ,    byte currentValue ) Return the value for the field . Parameters: pc - the calling PersistenceCapable instance field - the field number currentValue - the current value of the field Return: the new value for the field Since: JDO 1.0

;pc,    int  field ,    char currentValue ) Return the value for the field . Parameters: pc - the calling PersistenceCapable instance field - the field number currentValue - the current value of the field Return: the new value for the field Since: JDO 1.0

JDO Method in javax.jdo.spi.StateManager Object replacingObjectField (   PersistenceCapable pc,    int  field ) The replacement value of the field in the calling instance. Parameters: pc - the calling PersistenceCapable instance field - the field number Return: the new value for the field Since: JDO 1.0

JDO Method in javax.jdo.spi.StateManager String replacingStringField (   PersistenceCapable pc,    int  field ) The replacement value of the field in the calling instance. Parameters: pc - the calling PersistenceCapable instance field - the field number Return: the new value for the field Since: JDO 1.0

 pc,    int  field ,    long currentValue ) The value of the field requested to be provided to the StateManager . Parameters: pc - the calling PersistenceCapable instance field - the field number currentValue - the current value of the field Since: JDO 1.0

 pc,    int  field ,    int currentValue ) The value of the field requested to be provided to the StateManager . Parameters: pc - the calling PersistenceCapable instance field - the field number currentValue - the current value of the field Since: JDO 1.0

 pc,    int  field ,    char currentValue ) The value of the field requested to be provided to the StateManager . Parameters: pc - the calling PersistenceCapable instance field - the field number currentValue - the current value of the field Since: JDO 1.0

;PersistenceCapable pc,    int  field ,    boolean currentValue ) The value of the field requested to be provided to the StateManager . Parameters: pc - the calling PersistenceCapable instance field - the field number currentValue - the current value of the field Since: JDO 1.0

 pc,    int  field ,    short currentValue ) The value of the field requested to be provided to the StateManager . Parameters: pc - the calling PersistenceCapable instance field - the field number currentValue - the current value of the field Since: JDO 1.0

 pc,    int  field ,    byte currentValue ) The value of the field requested to be provided to the StateManager . Parameters: pc - the calling PersistenceCapable instance field - the field number currentValue - the current value of the field Since: JDO 1.0

JDO Method in javax.jdo.spi.StateManager long replacingLongField (   PersistenceCapable pc,    int  field ) The replacement value of the field in the calling instance. Parameters: pc - the calling PersistenceCapable instance field - the field number Return: the new value for the field Since: JDO 1.0

JDO Method in javax.jdo.spi.StateManager double replacingDoubleField (   PersistenceCapable pc,    int  field ) The replacement value of the field in the calling instance. Parameters: pc - the calling PersistenceCapable instance field - the field number Return: the new value for the field Since: JDO 1.0

JDO Method in javax.jdo.spi.StateManager float replacingFloatField (   PersistenceCapable pc,    int  field ) The replacement value of the field in the calling instance. Parameters: pc - the calling PersistenceCapable instance field - the field number Return: the new value for the field Since: JDO 1.0