请教一个hibernate递归映射的问题.

Question

看下我的这个帖子，用hibernate实现树状结构。
http://blog.csdn.net/pizzame/archive/2007/10/09/1816811.aspx

Answer 1

 mappedBy reference an unknown target entity property: shadowingfly.Employee.parent in shadowingfly.Department.children

Answer 2

照LS说的我尝试了自己对自己双向多对一不行package shadowingfly;import java.util.Set;import javax.persistence.CascadeType;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.persistence.OneToMany;
import javax.persistence.Transient;@Entity
public class Department {
private int id;
private Department parent;
    private Set<Employee> children; //通过Set将下级加入该实体 private String name;
private boolean isRoot;
private String description;// 备注
public Department() { }
@OneToMany(cascade = CascadeType.ALL,mappedBy ="parent" )
public Set<Employee> getChildren() {
return children;
} public void setChildren(Set<Employee> children) {
this.children = children;
} @Id
@GeneratedValue(strategy = GenerationType.TABLE)
public int getId() {
return id;
} public void setId(int id) {
this.id = id;
} @ManyToOne
@JoinColumn
public Department getParent() {

return parent;
}
     
public void setParent(Department parent)
{
this.parent = parent;

} public String getName() {
return name;
} public void setName(String name) {
this.name = name;
} public boolean isRoot() {
return isRoot;
} public void setRoot(boolean isRoot) {
this.isRoot = isRoot;
} public String getDescription() {
return description;
} public void setDescription(String description) {
this.description = description;
} @Transient
public boolean isTransient() {
return getId() < 1;
}}

Answer 3

搞定了...谢谢
pizzame
结贴package shadowingfly;import java.util.Set;import javax.persistence.CascadeType;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.persistence.OneToMany;
import javax.persistence.Transient;@Entity
public class Department {
private int id;
private Department parent;
    private Set<Department> children; //通过Set将下级加入该实体 private String name;
private boolean isRoot;
private String description;// 备注
public Department() { }
@OneToMany(cascade = CascadeType.ALL,mappedBy ="parent" )
public Set<Department> getChildren() {
return children;
} public void setChildren(Set<Department> children) {
this.children = children;
} @Id
@GeneratedValue(strategy = GenerationType.TABLE)
public int getId() {
return id;
} public void setId(int id) {
this.id = id;
} @ManyToOne
@JoinColumn
public Department getParent() {

return parent;
}
     
public void setParent(Department parent)
{
this.parent = parent;

} public String getName() {
return name;
} public void setName(String name) {
this.name = name;
} public boolean isRoot() {
return isRoot;
} public void setRoot(boolean isRoot) {
this.isRoot = isRoot;
} public String getDescription() {
return description;
} public void setDescription(String description) {
this.description = description;
} @Transient
public boolean isTransient() {
return getId() < 1;
}}

Answer 4

这样映射造成这个表drop不了了...

Answer 5

详细描述下，如果是因为级联问题而导致的drop不了，一般要将你在关系数据库中的关系全部去掉。