如何与nhibernate保持多对多关系同步?
我正在为员工和部门两个对象创建数据模型。员工有一个部门列表,部门有一个员工列表如何与nhibernate保持多对多关系同步?,nhibernate,fluent-nhibernate,fluent-nhibernate-mapping,Nhibernate,Fluent Nhibernate,Fluent Nhibernate Mapping,我正在为员工和部门两个对象创建数据模型。员工有一个部门列表,部门有一个员工列表 class Employee{ private IList<Department> _departments; public Employee() { _departments = new List<Department>(); } public virtual ReadOnlyCol
class Employee{
private IList<Department> _departments;
public Employee()
{
_departments = new List<Department>();
}
public virtual ReadOnlyCollection<Department> Departments{
get {return new ReadOnlyCollection<Department>(_departments);}
}
}
class Department{
private IList<Employee> _employees;
public Department()
{
_departments = new List<Employee>();
}
public virtual ReadOnlyCollection<Employee> Employees{
get {return new ReadOnlyCollection<Employee>(_employees);}
}
}
但是它没有像我预期的那样工作。有人能帮忙吗。这是我如何处理这些关系的一个例子:
public class User
{
private IList<Group> groups;
public virtual IEnumerable<Group> Groups { get { return groups.Select(x => x); } }
public virtual void AddGroup(Group group)
{
if (this.groups.Contains(group))
return;
this.groups.Add(group);
group.AddUser(this);
}
public virtual void RemoveGroup(Group group)
{
if (!this.groups.Contains(group))
return;
this.groups.Remove(group);
group.RemoveUser(this);
}
}
我的组
映射如下所示:
public class GroupMap : ClassMap<Group>
{
public GroupMap()
{
//Id, Table etc have been omitted
HasManyToMany(x => x.Users)
.Table("USER_GROUP_COMPOSITE")
.ParentKeyColumn("GROUP_ID")
.ChildKeyColumn("USER_ID")
.Access.CamelCaseField();
}
}
公共类组映射:类映射
{
公共组映射()
{
//省略了Id、表格等
HasManyToMany(x=>x.Users)
.表格(“用户组组合”)
.ParentKeyColumn(“组ID”)
.ChildKeyColumn(“用户ID”)
.Access.CamelCaseField();
}
}
我在下面发布了一个关于如何处理这些场景的示例,但为什么您的代码不能按预期工作?您期望的是什么?当我试图像db.session.save(Employee)那样保存时,它会导致循环依赖;员工有部门,部门内部有员工,等等。。它是圆形的。我不确定这是否正确。如果我错了,有人能纠正我吗?我的做法完全相同,至少这将样板代码与应用程序代码分开,并给您一个单一的故障点。您甚至可以向Group类中添加方便的方法(Add,Remove)来删除用户。@SebastianEdelmeier,该类中有一些方法可以做到这一点。add和remove都调用上述代码中组中的那些方法。
public class UserMap : ClassMap<User>
{
public UserMap()
{
//Id, Table etc have been omitted
HasManyToMany(x => x.Groups)
.Table("USER_GROUP_COMPOSITE")
.ParentKeyColumn("USER_ID")
.ChildKeyColumn("GROUP_ID")
.Access.CamelCaseField()
.Cascade.SaveUpdate()
.Inverse()
.FetchType.Join();
}
}
public class GroupMap : ClassMap<Group>
{
public GroupMap()
{
//Id, Table etc have been omitted
HasManyToMany(x => x.Users)
.Table("USER_GROUP_COMPOSITE")
.ParentKeyColumn("GROUP_ID")
.ChildKeyColumn("USER_ID")
.Access.CamelCaseField();
}
}