jpa嵌入式复合主键

jpa嵌入式复合主键：

 

JPA生成的实体要求有主键，如果数据库没有的话可以自己构造一个主键,只是为了符合jpa规范，xml中还是以数据库为主

用于构造主键的实体的那个类需要无参数构造函数，重写equals，hashcode（构造主键的实体）,实现序列化

 

 

（1）通过@EmbeddedId注释标注实体中的嵌入式主键

 

注意：

1.必须要实现serializable接口

 

2.需要有无参的构造函数

 

3.@Embeddable注释,表示此类可以被插入某个entity中

 

4.两个class和Column的列名都必需与表里的列名一致，建立sql时，会自动选择TestPK里的列名 

http://vaadin.iteye.com/blog/1317227

 

<resultMap type="com.esteel.web.beanvo.TbCusTradeWareBeanVo"

id="tbCusTradeWareMap">

<!-- <result property="id" column="id" typeHandler="com.esteel.web.entity.TbCusTradeWareBeanPK" /> -->不需要写

<result property="addTime" column="ADD_TIME" />

<result property="cusTradeKind" column="CUS_TRADE_KIND" />

<result property="currencyType" column="CURRENCY_TYPE" />

<result property="cusUserKey" column="CUS_USER_KEY" />/////////////这两个主键一定要写在结果集中否者主键类接不到返回值

<result property="customerKey" column="CUSTOMER_KEY" />

<result property="remark" column="remark" />

<result property="tradeType" column="TRADE_TYPE" />

<result property="warekindKey" column="WAREKIND_KEY" />

<result property="currencyName" column="WAREKIND_NAME" />

</resultMap>

 

 结果集中的主键是以一个对象嵌入返回（类似一对一关联）

 

 

 

 

 

 

 

 

 

package com.esteel.web.entity;

 

import java.io.Serializable;

import javax.persistence.*;

 

import oracle.net.aso.i;

 

import java.math.BigDecimal;

import java.util.Date;

 

 

/**

 * The persistent class for the TB_CUS_TRADE_WARE database table.

 * 

 */

@Entity

@Table(name="TB_CUS_TRADE_WARE")

@NamedQuery(name="TbCusTradeWareBean.findAll", query="SELECT t FROM TbCusTradeWareBean t")

public class TbCusTradeWareBean implements Serializable {

private static final long serialVersionUID = 1L;

 

@EmbeddedId

// @AttributeOverrides( {

//

//       @AttributeOverride(name = "cusUserKey", column = @Column(name = "CUS_USER_KEY")),

//

//       @AttributeOverride(name = "customerKey", column = @Column(name = "CUSTOMER_KEY")) })主键类中有写就不要

private TbCusTradeWareBeanPK id =new TbCusTradeWareBeanPK();//////////给主键赋值一定要new 符合主键

 

 

public TbCusTradeWareBeanPK getId() {

 

 return id;

 

}

 

@Temporal(TemporalType.DATE)

@Column(name="ADD_TIME")

private Date addTime;

 

@Column(name="CURRENCY_TYPE")

private String currencyType;

 

 

 

private String remark;

 

@Column(name="TRADE_TYPE")

private String tradeType;

 

@Column(name="WAREKIND_KEY")

private BigDecimal warekindKey;

 

public TbCusTradeWareBean() {

}

 

public Date getAddTime() {

return this.addTime;

}

 

public void setAddTime(Date addTime) {

this.addTime = addTime;

}

 

public String getCurrencyType() {

return this.currencyType;

}

 

public void setCurrencyType(String currencyType) {

this.currencyType = currencyType;

}

 

 

 

public void setId(TbCusTradeWareBeanPK id) {

this.id = id;

}

 

public String getRemark() {

return this.remark;

}

 

public void setRemark(String remark) {

this.remark = remark;

}

 

public String getTradeType() {

return this.tradeType;

}

 

public void setTradeType(String tradeType) {

this.tradeType = tradeType;

}

 

public BigDecimal getWarekindKey() {

return this.warekindKey;

}

 

public void setWarekindKey(BigDecimal warekindKey) {

this.warekindKey = warekindKey;

}

//@Column(name="CUS_USER_KEY")

public BigDecimal getCusUserKey() {

return id.getCusUserKey();

}

 

public void setCusUserKey(BigDecimal cusUserKey) {

id.setCusUserKey(cusUserKey);

}

//@Column(name="CUSTOMER_KEY")

public BigDecimal getCustomerKey() {

return id.getCustomerKey();

}

 

public void setCustomerKey(BigDecimal customerKey) {

id.setCustomerKey(customerKey); 

}

}

 

 

 

 

 

 

 

 

（2）作为嵌入式主键类，要满足以下几点要求。

 

1.必须实现Serializable接口、必须有默认的public无参数的构造方法、必须覆盖equals 和hashCode方法，这些要求与使用复合主键的要求相同。

 

2.将嵌入式主键类使用@Embeddable标注，表示这个是一个嵌入式类。

 

package com.esteel.web.entity;

 

import java.io.Serializable;

import java.math.BigDecimal;

 

import javax.persistence.Column;

import javax.persistence.Embeddable;

 

 

/**

 * The persistent class for the TB_CUS_TRADE_WARE database table.

 * 

 */

@Embeddable

public class TbCusTradeWareBeanPK implements Serializable {

private static final long serialVersionUID = 1L;

 

@Column(name="CUS_USER_KEY")

private BigDecimal cusUserKey;

 

@Column(name="CUSTOMER_KEY")

private BigDecimal customerKey;

 

 

 

public TbCusTradeWareBeanPK() {

}

 

public TbCusTradeWareBeanPK(BigDecimal cusUserKey,BigDecimal customerKey) {

this.customerKey=cusUserKey;

this.cusUserKey=cusUserKey;

}

public BigDecimal getCusUserKey() {

return cusUserKey;

}

 

public void setCusUserKey(BigDecimal cusUserKey) {

this.cusUserKey = cusUserKey;

}

 

public BigDecimal getCustomerKey() {

return customerKey;

}

 

public void setCustomerKey(BigDecimal customerKey) {

this.customerKey = customerKey;

}

public boolean equals(Object other) {

if (this == other) {

return true;

}

if (!(other instanceof TbCusTradeWareBeanPK)) {

return false;

}

TbCusTradeWareBeanPK castOther = (TbCusTradeWareBeanPK)other;

return 

(this.cusUserKey == castOther.cusUserKey)

&& this.customerKey.equals(castOther.customerKey);

}

 

public int hashCode() {

final int prime = 31;

int hash = 17;

hash = this.cusUserKey.hashCode();

hash = hash * prime + this.customerKey.hashCode();

return hash;

}

 

 

}