@Id@GeneratedValue@Column(name="RecId")publicintgetRecId(){returnRecId;}

　　复合主键个人认为用到的很少，呜呜还是碰到了，由于没有经验，东装西摸，浪费了很长时间才把复合主键配好了，并且还出了很多异常，如下所示：

　　一个表中可以有多个字段組成的主鍵

createtableEL_TransIdTable(TableNamenvarchar(50),LastTransIdnvarchar(15),Prefixnchar(5),DomainIdnvarchar(10)primarykey(TableName,DomainId))

　　其中TableName、DomainId两个字段作为此表的主键。

　　在配置中主要分为两个步骤：

　　1为复合主键，建立一个复合主键类，这个类包括两个字段，(有几个字段组成主键就包含几个字段)这个复合主键类实现Serializable接口，有public无参的构造方法重写equals和hashcode方法。

　　2：在实体类里面用idclass标示复合主键类详情如下：

　　新建复合主键类TableDomainIdPK.java。

packagecom.barcode.Model;importjava.io.Serializable;publicclassTableNameDomainIdPKimplementsSerializable{publicTableNameDomainIdPK(){}privateStringTableName;privateStringDomainId;publicStringgetTableName(){returnTableName;}publicvoidsetTableName(StringtableName){TableName=tableName;}publicStringgetDomainId(){returnDomainId;}publicvoidsetDomainId(StringdomainId){DomainId=domainId;}@OverridepublicinthashCode(){finalintPRIME=31;intresult=1;result=PRIME*result+((TableName==null)0:TableName.hashCode());result=PRIME*result+((DomainId==null)0:DomainId.hashCode());returnresult;}@Overridepublicbooleanequals(java.lang.Objectobj){if(this==obj){returntrue;}if(null==obj){returnfalse;}finalTableNameDomainIdPKother=(TableNameDomainIdPK)obj;if(DomainId==null){if(other.DomainId!=null){returnfalse;}}elseif(!DomainId.equals(other.DomainId)){returnfalse;}if(TableName==null){if(other.TableName!=null){returnfalse;}}elseif(!TableName.equals(other.TableName)){returnfalse;}returntrue;}}

　　新建实体类EL_TransIdTable.java。

　　SQLServer数据库主键及复合主键有哪些配置

　　实体类中的配置如下：

packagecom.barcode.Model;importjava.io.Serializable;importjavax.persistence.Column;importjavax.persistence.Entity;importjavax.persistence.Id;importjavax.persistence.IdClass;importjavax.persistence.Table;@Entity@Table(name="EL_TransIdTable")@IdClass(TableNameDomainIdPK.class)publicclassEL_TransIdTableimplementsSerializable{privateStringTableName;privateStringLastTransId;privateStringPrefix;privateStringDomainId;@Id@Column(name="TableName",nullable=false)publicStringgetTableName(){returnTableName;}publicvoidsetTableName(StringtableName){TableName=tableName;}@Column(name="LastTransId")publicStringgetLastTransId(){returnLastTransId;}publicvoidsetLastTransId(StringlastTransId){LastTransId=lastTransId;}@Column(name="Prefix")publicStringgetPrefix(){returnPrefix;}publicvoidsetPrefix(Stringprefix){Prefix=prefix;}@Id@Column(name="DomainId",nullable=false)publicStringgetDomainId(){returnDomainId;}publicvoidsetDomainId(StringdomainId){DomainId=domainId;}publicvoidPrint_Info(){System.out.println(this.getDomainId()+this.getLastTransId()+this.getPrefix()+this.getTableName());}}