JPA hibernate 主键生成计策

2013-07-16

JPA hibernate 主键生成策略@Id@GeneratedValue(generator gen)@GenericGenerator(name gen, stra

JPA hibernate 主键生成策略
@Id@GeneratedValue(generator = "gen") @GenericGenerator(name = "gen", strategy = "native")

?或

@Id@GeneratedValue(strategy=GenerationType.AUTO)

2.table?:??org.hibernate.id.enhanced.TableGenerator

@Id@GeneratedValue(strategy=GenerationType.TABLE, generator="empGen")@TableGenerator(            name="empGen",             table="ID_GEN",             pkColumnName="GEN_KEY",             valueColumnName="GEN_VALUE",             pkColumnValue="EMP_ID",             allocationSize=1)public int id;

3.uuid :?org.hibernate.id.UUIDHexGenerator

最高生成36位长唯一字符串（加上分隔符），默认32位

@Id  @GeneratedValue(generator = "gen")       @GenericGenerator(name = "gen", strategy = "uuid",parameters={//@Parameter(name="separator",value="自定义分隔符，长度1位")})private String id;

4.hilo?:?org.hibernate.id.TableHiLoGenerator

@Id@GeneratedValue(generator="gen")@GenericGenerator(name="gen",strategy="hilo",parameters={//@Parameter(name="table",value="hibernate_unique_key"),   //@Parameter(name="column",value="next_hi"),//@Parameter(name="schema",value="schema"),//@Parameter(name="catalog",value="catalog"),//@Parameter(name="max_lo",value="20")})private int id;

?注释部分可以做相应的修改

5.assigned?:?org.hibernate.id.Assigned?

@Idprivate int id;

6.identity?:?org.hibernate.id.IdentityGenerator

@Id@GeneratedValue(strategy=GenerationType.IDENTITY)private int id;

7.select?:?org.hibernate.id.SelectGenerator

8.sequence?:?org.hibernate.id.SequenceGenerator

@Id@GeneratedValue(generator="gen")@GenericGenerator(name="gen",strategy="sequence",parameters={//@Parameter(name="sequence",value="hibernate_sequence"),//@Parameter(name="parameters",value=""),//@Parameter(name="schema",value=""),//@Parameter(name="catalog",value="")})private int id;

或

@Id@GeneratedValue(strategy=GenerationType.SEQUENCE)private int id;

支持DB2.H2.HSQL.Informix.Ingres.Interbase.Mckoi.Mimer.Oracle.Postgre.RDMSOS2200.SAPDB.TimesTen

9.seqhilo?:?org.hibernate.id.SequenceHiLoGenerator

@Id@GeneratedValue(generator="gen")@GenericGenerator(name="gen",strategy="seqhilo",parameters={//@Parameter(name="sequence",value="hibernate_sequence"),//@Parameter(name="parameters",value=""),//@Parameter(name="schema",value=""),//@Parameter(name="catalog",value=""),//@Parameter(name="max_lo",value="20")})private int id;

支持DB2.H2.HSQL.Informix.Ingres.Interbase.Mckoi.Mimer.Oracle.Postgre.RDMSOS2200.SAPDB.TimesTen

10.increment?:?org.hibernate.id.IncrementGenerator

@Entity@Table(name = "id_increment_gen")public class IncrementGen {@Id@GeneratedValue(generator="gen")@GenericGenerator(name="gen",strategy="increment",parameters={@Parameter(name="tables",value="id_increment_gen"),//@Parameter(name="identity_tables",value="id_increment_gen"),@Parameter(name="column",value="id"),//@Parameter(name="target_column",value="id"),//@Parameter(name="schema",value=""),//@Parameter(name="catalog",value="")})private int id;

? ?其中tables参数和identity_tables参数互斥，tables参数优先。column参数和target_column参数互斥， ? column参数优先，支持多表，以","分隔，会生成类似如下的语句：

select max (ids_.id) from ( select id from id_increment_gen ) ids_

?多表时为：

select max (ids_.id) from ( select id from id_increment_gen1 union select id from id_increment_gen2 ) ids_

11.foreign?:?org.hibernate.id.?ForeignGenerator?

12.guid?:?org.hibernate.id.?GUIDGenerator

@Id@GeneratedValue(generator = "gen")     @GenericGenerator(name = "gen", strategy = "guid")private String id;

?支持mysql,oracle,sybase

13.uuid.hex?:?org.hibernate.id.UUIDHexGenerator? // uuid.hex is deprecated

14.sequence-identity?:?org.hibernate.id.SequenceIdentityGenerator

15.自定义

可同时实现接口org.hibernate.id.IdentifierGenerator，org.hibernate.id.Configurable

@Id@GeneratedValue(generator = "gen")     @GenericGenerator(name = "gen", strategy = "xg.CustGenerator")private String id;

?strategy填写具体类名?

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JPA hibernate 主键生成计策