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笔记：Hibernate 持久化类标注示例-双向1-N关系映射
- 1-N关系的1端持久化类
package org.drsoft.hibernate.model.oneToMany;
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import java.util.Date;
import java.util.Set;
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import javax.persistence.*;
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@Entity
@Table(name = "OneToMany_One")
public class OneToManyForOneModel {
@Id
@Column(name = "Record_ID")
@GeneratedValue(strategy = GenerationType.IDENTITY)
private int recordID;
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@Column(name = "Total_Trade_Amt")
private long totalTradeAmt;
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@Column(name = "Modify_Time")
private Date modifyTime;
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@Column(name = "Create_Time", insertable = false, updatable = false)
private Date createTime;
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@OneToMany(cascade = {
CascadeType.PERSIST }, fetch = FetchType.LAZY, targetEntity = OneToManyForManyModel.class, orphanRemoval = false,mappedBy="oneToManyForOneModel")
private Set<OneToManyForManyModel> details;
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省略setter和getter
}
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- 1-N关系的N端持久化类
package org.drsoft.hibernate.model.oneToMany;
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import java.util.Date;
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import javax.persistence.*;
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@Entity
@Table(name = "OneToMany_Many")
public class OneToManyForManyModel {
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@Id
@Column(name = "Detail_ID")
@GeneratedValue(strategy = GenerationType.IDENTITY)
private int detailID;
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@Column(name = "Trade_Amt")
private long tradeAmt;
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@Column(name = "Create_Time", insertable = false, updatable = false)
private Date createTime;
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@ManyToOne
@JoinColumn(name = "Ref_Record_ID", referencedColumnName = "Record_ID")
private OneToManyForOneModel oneToManyForOneModel;
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省略setter和getter
}
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- 测试调用
package org.drsoft.hibernate.manager.oneToMany;
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import java.util.*;
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import org.drsoft.hibernate.model.oneToMany.*;
import org.drsoft.utils.hibernateUtils;
import org.hibernate.Session;
import org.hibernate.Transaction;
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public class OneToManyManager {
public static void main(String[] args) {
Session curSession = hibernateUtils.openSession();
Transaction curTransaction = null;
Calendar calendar = Calendar.getInstance(Locale.CHINA);
try {
System.out.println("#1 创建 One 和 Many数据");
// #1 创建 One 和 Many数据
OneToManyForOneModel oneToManyForOneModel = new OneToManyForOneModel();
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long totalTradeAmt = 0;
for (int i = 0; i < 5; i++) {
OneToManyForManyModel oneToManyForManyModel = new OneToManyForManyModel();
oneToManyForManyModel.setTradeAmt(calendar.get(Calendar.SECOND) + i);
totalTradeAmt = totalTradeAmt + oneToManyForManyModel.getTradeAmt();
if (oneToManyForOneModel.getDetails() == null) {
oneToManyForOneModel.setDetails(new HashSet<OneToManyForManyModel>());
System.out.println("创建 HashSet<OneToManyForManyModel>()");
}
oneToManyForOneModel.getDetails().add(oneToManyForManyModel);
}
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oneToManyForOneModel.setTotalTradeAmt(totalTradeAmt);
oneToManyForOneModel.setModifyTime(new Date());
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curTransaction = hibernateUtils.beginTransaction(curSession);
curSession.persist(oneToManyForOneModel);
curTransaction.commit();
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System.out.println("#2 查询 One 数据");
// #2 查询 One 数据
oneToManyForOneModel = (OneToManyForOneModel) curSession.load(OneToManyForOneModel.class, new Integer(1));
System.out.println("OneToManyForOneModel RecordID=" + oneToManyForOneModel.getRecordID()
+ "\tTotalTradeAmt=" + oneToManyForOneModel.getTotalTradeAmt());
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Set<OneToManyForManyModel> details = oneToManyForOneModel.getDetails();
Iterator<OneToManyForManyModel> it = details.iterator();
while (it.hasNext()) {
OneToManyForManyModel obj = it.next();
System.out.println(
"OneToManyForManyModel DetailID=" + obj.getDetailID() + "\tTradeAmt=" + obj.getTradeAmt());
}
} catch (Exception e) {
if (curTransaction != null && curTransaction.isActive()) {
curTransaction.rollback();
}
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throw e;
} finally {
if (curSession != null) {
curSession.close();
}
}
}
}
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笔记：Hibernate 持久化类标注示例-双向1-N关系映射