GeneratedValue
annotation. A sequence generator may be specified on the entity
class or on the primary key field or property. The scope of the
generator name is global to the persistence unit (across all
generator types).
If no name is explicitly specified, and the annotation occurs on an entity class or primary key attribute of an entity class, then the name defaults to the name of the entity.
If no name is explicitly specified, and the annotation occurs
on a package descriptor, then the annotation defines a recipe for
producing a default generator when a GeneratedValue
annotation of any program element in the annotated package has
strategy=SEQUENCE and a defaulted
generator name. The name of
this default generator is the defaulted generator name, and its
other properties are determined by the members of the package
SequenceGenerator annotation.
Example:
@SequenceGenerator(name = "EMP_SEQ", allocationSize = 25)
| Modifier and Type | Method and Description |
|---|---|
| public int | allocationSize()
(Optional) The amount to increment by when allocating sequence numbers from the sequence. |
| public String | |
| public int | |
| public String | name()
(Optional) A unique generator name that can be referenced by one or more classes to be the generator for primary key values. |
| public String | options()
(Optional) A SQL fragment appended to the generated DDL statement which creates this sequence. |
| public String | |
| public String | sequenceName()
(Optional) The name of the database sequence object from which to obtain primary key values. |
| allocationSize | back to summary |
|---|---|
| public int allocationSize() (Optional) The amount to increment by when allocating sequence numbers from the sequence. | |
| catalog | back to summary |
|---|---|
| public String catalog() (Optional) The catalog of the sequence generator.
| |
| initialValue | back to summary |
|---|---|
| public int initialValue() (Optional) The value from which the sequence object is to start generating. | |
| name | back to summary |
|---|---|
| public String name() (Optional) A unique generator name that can be referenced by one or more classes to be the generator for primary key values. Defaults to the name of the entity when the annotation occurs on an entity class or primary key attribute. | |
| options | back to summary |
|---|---|
| public String options() (Optional) A SQL fragment appended to the generated DDL statement which creates this sequence.
| |
| schema | back to summary |
|---|---|
| public String schema() (Optional) The schema of the sequence generator.
| |
| sequenceName | back to summary |
|---|---|
| public String sequenceName() (Optional) The name of the database sequence object from which to obtain primary key values. Defaults to a provider-chosen value. | |