mysql hibernate id generator,hibernate annoation (三 id生成器)

id生成：

hibernate内不可使用的id生成器可见代码

使用@GeneratedValue

1 正对不同的数据库可以同时使用

@Id

@GeneratedValue(strategy = GenerationType.AUTO)

2 针对mysql

@Id

@GeneratedValue(strategy = GenerationType.IDENTITY)

3 针对oracle

@Id

@GeneratedValue(strategy = GenerationType.SEQUENCE,generator="s_gen")

@SequenceGenerator(name="s_gen",sequenceName="s_seq")

说明：@GeneratedValue()的strategy属性支持5中id生成器：除上面3中外还有GenerationType.TABLE

2配合使用@GenericGenerator 不单独使用

hibernate内不可使用的id生成器可见代码

GENERATORS.put( "uuid", UUIDHexGenerator.class );

GENERATORS.put( "hilo", TableHiLoGenerator.class );

GENERATORS.put( "assigned", Assigned.class );

GENERATORS.put( "identity", IdentityGenerator.class );

GENERATORS.put( "select", SelectGenerator.class );

GENERATORS.put( "sequence", SequenceGenerator.class );

GENERATORS.put( "seqhilo", SequenceHiLoGenerator.class );

GENERATORS.put( "increment", IncrementGenerator.class );

GENERATORS.put( "foreign", ForeignGenerator.class );

GENERATORS.put( "guid", GUIDGenerator.class );

GENERATORS.put( "uuid.hex", UUIDHexGenerator.class );  // uuid.hex is deprecated

GENERATORS.put( "sequence-identity", SequenceIdentityGenerator.class );

)

如果想要不同的表使用相同的主键生成器，可以把他的generator的name属性设为相同即可

例如：

@GeneratedValue(name="id1")

@GenericGenerator(name="id1",strategy="identity")

1、native

@GeneratedValue(generator = "paymentableGenerator") @GenericGenerator(name = "paymentableGenerator", strategy = "native")

2、uuid

@GeneratedValue(generator = "paymentableGenerator") @GenericGenerator(name = "paymentableGenerator", strategy = "uuid")

3、hilo

@GeneratedValue(generator = "paymentableGenerator") @GenericGenerator(name = "paymentableGenerator", strategy = "hilo")

4、assigned

@GeneratedValue(generator = "paymentableGenerator") @GenericGenerator(name = "paymentableGenerator", strategy = "assigned")

5、identity

@GeneratedValue(generator = "paymentableGenerator") @GenericGenerator(name = "paymentableGenerator", strategy = "identity")

6、select

@GeneratedValue(generator = "paymentableGenerator") @GenericGenerator(name="select", strategy="select", parameters = { @Parameter(name = "key", value = "idstoerung") })

7、sequence

Java代码

@GeneratedValue(generator = "paymentableGenerator") @GenericGenerator(name = "paymentableGenerator", strategy = "sequence", parameters = { @Parameter(name = "sequence", value = "seq_payablemoney") })

8、seqhilo

@GeneratedValue(generator = "paymentableGenerator") @GenericGenerator(name = "paymentableGenerator", strategy = "seqhilo", parameters = { @Parameter(name = "max_lo", value = "5") })

9、increment

Java代码

@GeneratedValue(generator = "paymentableGenerator") @GenericGenerator(name = "paymentableGenerator", strategy = "increment")