java hibernate使用注解來定義聯(lián)合主鍵
java hibernate使用注解來定義聯(lián)合主鍵
下面使用hibernate的API中說明的三種方式來定義主鍵,主要使用Annotation來定義hibernate中的聯(lián)合主鍵
下面取至hibernate的API文檔:
定義組合主鍵的幾種語法:
1、將組件類注解為@Embeddable,并將組件的屬性注解為@Id
2、將組件的屬性注解為@EmbeddedId
3、將類注解為@IdClass,并將該實體中所有屬于主鍵的屬性都注解為@Id
下面就分別使用這三種方式來定義聯(lián)合主鍵。
建表的SQL語句:
CREATE TABLE `syslogs` ( `id` varchar(50) NOT NULL, `yhid` varchar(50) NOT NULL, `modelname` varchar(100) DEFAULT NULL, `content` varchar(500) DEFAULT NULL, `inserttime` varchar(20) DEFAULT NULL, `remark` varchar(50) DEFAULT NULL, PRIMARY KEY (`id`,`yhid`) ) ENGINE=InnoDB DEFAULT CHARSET=utf-8;
一、將組件類注解為@Embeddable
/**
* SysLogsDtoId代表主鍵類
*/
package com.hibernate.dto;
import javax.persistence.Embeddable;
/**
* 1、主鍵類必須要實現(xiàn)java.io.Serializable接口
* 2、主鍵類必須要重寫equals和hashCode方法
* @author ibm
*/
@Embeddable
public class SysLogsDtoId implements java.io.Serializable {
private static final long serialVersionUID = 1L;
private String id;
private String yhid;
public SysLogsDtoId() {
}
public SysLogsDtoId(String id, String yhid) {
this.id = id;
this.yhid = yhid;
}
public String getId() {
return this.id;
}
public void setId(String id) {
this.id = id;
}
public String getYhid() {
return this.yhid;
}
public void setYhid(String yhid) {
this.yhid = yhid;
}
public boolean equals(Object other) {
if ((this == other))
return true;
if ((other == null))
return false;
if (!(other instanceof SysLogsDtoId))
return false;
SysLogsDtoId castOther = (SysLogsDtoId) other;
return ((this.getId() == castOther.getId()) || (this.getId() != null && castOther.getId() != null && this.getId().equals(castOther.getId())))
&& ((this.getYhid() == castOther.getYhid()) || (this.getYhid() != null && castOther.getYhid() != null && this.getYhid().equals(
castOther.getYhid())));
}
public int hashCode() {
int result = 17;
result = 37 * result + (getId() == null ? 0 : this.getId().hashCode());
result = 37 * result + (getYhid() == null ? 0 : this.getYhid().hashCode());
return result;
}
}
/**
* SysLogsDto為表對象映射類,其中主鍵為主鍵類SysLogsDtoId
*/
package com.hibernate.dto;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;
@Entity
@Table(name = "syslogs")
public class SysLogsDto implements java.io.Serializable {
private static final long serialVersionUID = 1L;
private SysLogsDtoId id;
private String modelname;
private String content;
private String inserttime;
private String remark;
public SysLogsDto() {
}
public SysLogsDto(SysLogsDtoId id) {
this.id = id;
}
public SysLogsDto(SysLogsDtoId id, String modelname, String content, String inserttime, String remark) {
this.id = id;
this.modelname = modelname;
this.content = content;
this.inserttime = inserttime;
this.remark = remark;
}
@Id
public SysLogsDtoId getId() {
return this.id;
}
public void setId(SysLogsDtoId id) {
this.id = id;
}
@Column(name = "modelname", length = 100)
public String getModelname() {
return this.modelname;
}
public void setModelname(String modelname) {
this.modelname = modelname;
}
@Column(name = "content", length = 500)
public String getContent() {
return this.content;
}
public void setContent(String content) {
this.content = content;
}
@Column(name = "inserttime", length = 20)
public String getInserttime() {
return this.inserttime;
}
public void setInserttime(String inserttime) {
this.inserttime = inserttime;
}
@Column(name = "remark", length = 50)
public String getRemark() {
return this.remark;
}
public void setRemark(String remark) {
this.remark = remark;
}
}
二、將組件的屬性注解為@EmbeddedId
這種情況最簡單,主鍵類只用定義主鍵字段,不需要寫任何注解。然后在對象類中在主鍵類的get方法上加上@EmbeddedId注解。
/**
* SysLogsDtoId代表主鍵類
*/
package com.hibernate.dto;
public class SysLogsDtoId implements java.io.Serializable {
private static final long serialVersionUID = 1L;
private String id;
private String yhid;
public SysLogsDtoId() {
}
public SysLogsDtoId(String id, String yhid) {
this.id = id;
this.yhid = yhid;
}
public String getId() {
return this.id;
}
public void setId(String id) {
this.id = id;
}
public String getYhid() {
return this.yhid;
}
public void setYhid(String yhid) {
this.yhid = yhid;
}
public boolean equals(Object other) {
if ((this == other))
return true;
if ((other == null))
return false;
if (!(other instanceof SysLogsDtoId))
return false;
SysLogsDtoId castOther = (SysLogsDtoId) other;
return ((this.getId() == castOther.getId()) || (this.getId() != null && castOther.getId() != null && this.getId().equals(castOther.getId())))
&& ((this.getYhid() == castOther.getYhid()) || (this.getYhid() != null && castOther.getYhid() != null && this.getYhid().equals(
castOther.getYhid())));
}
public int hashCode() {
int result = 17;
result = 37 * result + (getId() == null ? 0 : this.getId().hashCode());
result = 37 * result + (getYhid() == null ? 0 : this.getYhid().hashCode());
return result;
}
}
/**
* SysLogsDto為表對象映射類,其中主鍵為主鍵類SysLogsDtoId
*/
package com.hibernate.dto;
import javax.persistence.Column;
import javax.persistence.EmbeddedId;
import javax.persistence.Entity;
import javax.persistence.Table;
@Entity
@Table(name = "syslogs")
public class SysLogsDto implements java.io.Serializable {
private static final long serialVersionUID = 1L;
private SysLogsDtoId id;
private String modelname;
private String content;
private String inserttime;
private String remark;
public SysLogsDto() {
}
public SysLogsDto(SysLogsDtoId id) {
this.id = id;
}
public SysLogsDto(SysLogsDtoId id, String modelname, String content, String inserttime, String remark) {
this.id = id;
this.modelname = modelname;
this.content = content;
this.inserttime = inserttime;
this.remark = remark;
}
@EmbeddedId
public SysLogsDtoId getId() {
return this.id;
}
public void setId(SysLogsDtoId id) {
this.id = id;
}
@Column(name = "modelname", length = 100)
public String getModelname() {
return this.modelname;
}
public void setModelname(String modelname) {
this.modelname = modelname;
}
@Column(name = "content", length = 500)
public String getContent() {
return this.content;
}
public void setContent(String content) {
this.content = content;
}
@Column(name = "inserttime", length = 20)
public String getInserttime() {
return this.inserttime;
}
public void setInserttime(String inserttime) {
this.inserttime = inserttime;
}
@Column(name = "remark", length = 50)
public String getRemark() {
return this.remark;
}
public void setRemark(String remark) {
this.remark = remark;
}
}
三、將類注解為@IdClass,并將該實體中所有屬于主鍵的屬性都注解為@Id
/**
* SysLogsDtoId代表主鍵類
*/
package com.hibernate.dto;
public class SysLogsDtoId implements java.io.Serializable {
private static final long serialVersionUID = 1L;
private String id;
private String yhid;
public SysLogsDtoId() {
}
public SysLogsDtoId(String id, String yhid) {
this.id = id;
this.yhid = yhid;
}
public String getId() {
return this.id;
}
public void setId(String id) {
this.id = id;
}
public String getYhid() {
return this.yhid;
}
public void setYhid(String yhid) {
this.yhid = yhid;
}
public boolean equals(Object other) {
if ((this == other))
return true;
if ((other == null))
return false;
if (!(other instanceof SysLogsDtoId))
return false;
SysLogsDtoId castOther = (SysLogsDtoId) other;
return ((this.getId() == castOther.getId()) || (this.getId() != null && castOther.getId() != null && this.getId().equals(castOther.getId())))
&& ((this.getYhid() == castOther.getYhid()) || (this.getYhid() != null && castOther.getYhid() != null && this.getYhid().equals(
castOther.getYhid())));
}
public int hashCode() {
int result = 17;
result = 37 * result + (getId() == null ? 0 : this.getId().hashCode());
result = 37 * result + (getYhid() == null ? 0 : this.getYhid().hashCode());
return result;
}
}
/**
* SysLogsDto為表對象映射類,其中主鍵為主鍵類SysLogsDtoId
*/
package com.hibernate.dto;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.IdClass;
import javax.persistence.Table;
@Entity
@Table(name = "syslogs")
@IdClass(value=SysLogsDtoId.class)
public class SysLogsDto implements java.io.Serializable {
private static final long serialVersionUID = 1L;
private String id;
private String yhid;
private String modelname;
private String content;
private String inserttime;
private String remark;
public SysLogsDto() {
}
@Id
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
@Id
public String getYhid() {
return yhid;
}
public void setYhid(String yhid) {
this.yhid = yhid;
}
@Column(name = "modelname", length = 100)
public String getModelname() {
return this.modelname;
}
public void setModelname(String modelname) {
this.modelname = modelname;
}
@Column(name = "content", length = 500)
public String getContent() {
return this.content;
}
public void setContent(String content) {
this.content = content;
}
@Column(name = "inserttime", length = 20)
public String getInserttime() {
return this.inserttime;
}
public void setInserttime(String inserttime) {
this.inserttime = inserttime;
}
@Column(name = "remark", length = 50)
public String getRemark() {
return this.remark;
}
public void setRemark(String remark) {
this.remark = remark;
}
}
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