我试图通过DEPARTMENT（父）表将数据存储到EMPLOYEE（子）表中，并使用hibernate一对多的双向过程显示它。
在交易之后，我能够透露员工中的数据，包括我想要输入的数据，但我无法在数据库中看到该数据（POSTGRES）。请帮助我们，并提前致谢。
我有两个表部门（父母）和员工（子部门负责部门的dep_id）。
CREATE TABLE department
(
department_id character varying(10) NOT NULL,
department_name character varying(20),
CONSTRAINT "pk_departmentId" PRIMARY KEY (department_id)
)
CREATE TABLE employee
(
emp_id character varying(10) NOT NULL,
emp_name character varying(20),
department_id character varying(10),
CONSTRAINT "pk_empId" PRIMARY KEY (emp_id),
CONSTRAINT "fk_empDept" FOREIGN KEY (department_id) REFERENCES department (department_id) MATCH SIMPLE ON UPDATE NO ACTION ON DELETE NO ACTION
)
各个hbm文件是：
* DEPARTMENT *
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- Generated Oct 9, 2012 3:01:23 PM by Hibernate Tools 3.2.1.GA -->
<hibernate-mapping>
<class name="tablebeans.Department" table="department" schema="public">
<id name="departmentId" type="string">
<column name="department_id" length="10" />
<generator class="assigned" />
</id>
<property name="departmentName" type="string">
<column name="department_name" length="20" />
</property>
<set name="employees" table="employee" inverse="true" lazy="true" fetch="select">
<key>
<column name="department_id" length="10" />
</key>
<one-to-many class="tablebeans.Employee" />
</set>
</class>
</hibernate-mapping>
*的 EMPLOYEE *
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- Generated Oct 9, 2012 3:01:23 PM by Hibernate Tools 3.2.1.GA -->
<hibernate-mapping>
<class name="tablebeans.Employee" table="employee" schema="public">
<id name="empId" type="string">
<column name="emp_id" length="10" />
<generator class="assigned" />
</id>
<many-to-one name="department" class="tablebeans.Department" fetch="select">
<column name="department_id" length="10" />
</many-to-one>
<property name="empName" type="string">
<column name="emp_name" length="20" />
</property>
</class>
</hibernate-mapping>
POJO课程是：
package tablebeans;
// Generated Oct 9, 2012 3:01:23 PM by Hibernate Tools 3.2.1.GA
import java.util.HashSet;
import java.util.Set;
/**
* Department generated by hbm2java
*/
public class Department implements java.io.Serializable {
private String departmentId;
private String departmentName;
private Set employees = new HashSet(0);
public Department() {
}
public Department(String departmentId) {
this.departmentId = departmentId;
}
public Department(String departmentId, String departmentName, Set employees) {
this.departmentId = departmentId;
this.departmentName = departmentName;
this.employees = employees;
}
public String getDepartmentId() {
return this.departmentId;
}
public void setDepartmentId(String departmentId) {
this.departmentId = departmentId;
}
public String getDepartmentName() {
return this.departmentName;
}
public void setDepartmentName(String departmentName) {
this.departmentName = departmentName;
}
public Set getEmployees() {
return this.employees;
}
public void setEmployees(Set employees) {
this.employees = employees;
}
}
package tablebeans;
// Generated Oct 9, 2012 3:01:23 PM by Hibernate Tools 3.2.1.GA
/**
* Employee generated by hbm2java
*/
public class Employee implements java.io.Serializable {
private String empId;
private Department department;
private String empName;
public Employee() {
}
public Employee(String empId) {
this.empId = empId;
}
public Employee(String empId, Department department, String empName) {
this.empId = empId;
this.department = department;
this.empName = empName;
}
public String getEmpId() {
return this.empId;
}
public void setEmpId(String empId) {
this.empId = empId;
}
public Department getDepartment() {
return this.department;
}
public void setDepartment(Department department) {
this.department = department;
}
public String getEmpName() {
return this.empName;
}
public void setEmpName(String empName) {
this.empName = empName;
}
}
我试图通过DEPARTMENT表将数据存储到EMPLOYEE表并显示它的代码。
tx = session.beginTransaction();
Department department=new Department();
department.setDepartmentId("5");
department.setDepartmentName("Nielson");
Employee employee = new Employee();
employee.setEmpId("4");
employee.setEmpName("phani");
employee.setDepartment(department);
Set empset = new HashSet();
empset.add(employee);
department.setEmployees(empset);
session.save(department);
tx.commit();
//Query query = session.createQuery("insert into Department(departmentId,departmentName)"+"select departmentId,departmentName from Employee where departmentId = 5");
//int update = query.executeUpdate();
Query query1=session.createQuery("from Department");
List list1=query1.list();
for(int i=0;i<list1.size();i++)
{
System.out.println("In for");
Department department1 =(Department) list1.get(i);
System.out.println("the ID is "+department1.getDepartmentId());
System.out.println("the dept name is "+department1.getDepartmentName());
Set st = (Set) department1.getEmployees();
Iterator ite = st.iterator();
while(ite.hasNext())
{
employee = (Employee) ite.next();
System.out.println("the emp name is "+employee.getEmpName());
}
}
在这里，我能够将新输入的记录显示在employee表中，但该数据与数据库表中的数据不相似。我正在使用Postgres。
答案 0 :(得分：1)
仅在地图文件中添加 cascade =“save-update”。 对于部门来说，
<class name="tablebeans.Department" table="department" schema="public">
<id name="departmentId" type="string">
<column name="department_id" length="10" />
<generator class="assigned" />
</id>
<property name="departmentName" type="string">
<column name="department_name" length="20" />
</property>
<set name="employees" table="employee" inverse="true" lazy="true" fetch="select" cascade="save-update">
<key>
<column name="department_id" length="10" />
</key>
<one-to-many class="tablebeans.Employee" />
</set>
</class>
您可以在
中看到这一点