GenerationType (Java EE 5)

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javax.persistence Enum GenerationType

java.lang.Object
  java.lang.Enum<GenerationType>
      javax.persistence.GenerationType

All Implemented Interfaces:: Serializable, Comparable<GenerationType>

public enum GenerationType
extends Enum<GenerationType>

Extends: Enum<E>

定义主键生成的类型。

since

Java Persistence 1.0

英文文档：

Defines the types of primary key generation.

Since:: Java Persistence 1.0

Enum Constant Summary
`AUTO` Indicates that the persistence provider should pick an appropriate strategy for the particular database.
`IDENTITY` Indicates that the persistence provider must assign primary keys for the entity using database identity column.
`SEQUENCE` Indicates that the persistence provider must assign primary keys for the entity using database sequence column.
`TABLE` Indicates that the persistence provider must assign primary keys for the entity using an underlying database table to ensure uniqueness.

Method Summary
`static GenerationType`	`valueOf(String name)` Returns the enum constant of this type with the specified name.
`static GenerationType[]`	`values()` Returns an array containing the constants of this enum type, in the order they're declared.

Methods inherited from class java.lang.Enum
`clone, compareTo, equals, getDeclaringClass, hashCode, name, ordinal, toString, valueOf`

Methods inherited from class java.lang.Object
`finalize, getClass, notify, notifyAll, wait, wait, wait`

Enum Constant Detail

英文文档：

TABLE

public static final GenerationType TABLE

Indicates that the persistence provider must assign primary keys for the entity using an underlying database table to ensure uniqueness.

英文文档：

SEQUENCE

public static final GenerationType SEQUENCE

Indicates that the persistence provider must assign primary keys for the entity using database sequence column.

英文文档：

IDENTITY

public static final GenerationType IDENTITY

Indicates that the persistence provider must assign primary keys for the entity using database identity column.

英文文档：

AUTO

public static final GenerationType AUTO

Indicates that the persistence provider should pick an appropriate strategy for the particular database. The AUTO generation strategy may expect a database resource to exist, or it may attempt to create one. A vendor may provide documentation on how to create such resources in the event that it does not support schema generation or cannot create the schema resource at runtime.

Method Detail

final public static GenerationType[] values()

英文文档：
values

public static final GenerationType[] values()

Returns an array containing the constants of this enum type, in the order they're declared. This method may be used to iterate over the constants as follows:

for(GenerationType c : GenerationType.values())
        System.out.println(c);

Returns:: an array containing the constants of this enum type, in the order they're declared

public static GenerationType valueOf(String name)

英文文档：
valueOf

public static GenerationType valueOf(String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:: name - the name of the enum constant to be returned.
Returns:: the enum constant with the specified name
Throws:: IllegalArgumentException - if this enum type has no constant with the specified name