流利的NHibernate多对一映射 [英] Fluent NHibernate Many to one mapping

问题描述

我是休眠世界的新手.这可能是一个愚蠢的问题，但我无法解决.我正在测试表的多对一关系并尝试插入记录.我有一个Department表和Employee表.员工与部门在这里有多对一的关系.我正在使用Fluent NHibernate添加记录.下面的所有代码.请帮助

I am new to Hibernate world. It may be a silly question, but I am not able to solve it. I am testing many to One relationship of tables and trying to insert record. I have a Department table and Employee table. Employee and Dept has many to One relationship here. I am using Fluent NHibernate to add records. All codes below. Pls help

SQL代码

create table Dept (
    Id int primary key identity,
    DeptName varchar(20),
    DeptLocation varchar(20)
);

create table Employee (
    Id int primary key identity,
    EmpName varchar(20),
    EmpAge int,
    DeptId int references Dept(Id)
);

类文件

public partial class Dept
{
    public virtual System.String DeptLocation { get; set; }
    public virtual System.String DeptName { get; set; }
    public virtual System.Int32 Id { get; private  set; }
    public virtual IList<Employee> Employees { get; set; }
}

public partial class Employee
{
    public virtual System.Int32 DeptId { get; set; }
    public virtual System.Int32 EmpAge { get; set; }
    public virtual System.String EmpName { get; set; }
    public virtual System.Int32 Id { get; private set; }
    public virtual Project.Model.Dept Dept { get; set; }
}

映射文件

public class DeptMapping : ClassMap<Dept>   
{
    public DeptMapping()
    {
        Id(x => x.Id);
        Map(x => x.DeptName);
        Map(x => x.DeptLocation);
        HasMany(x => x.Employees).Inverse().Cascade.All();
    }
}

public class EmployeeMapping : ClassMap<Employee>
{
    public EmployeeMapping()
    {
        Id(x => x.Id);
        Map(x => x.EmpName);
        Map(x => x.EmpAge);
        Map(x => x.DeptId);
        References(x => x.Dept).Cascade.None();
    }
}

我要添加的代码

        try
        {
            Dept dept = new Dept();
            dept.DeptLocation = "Austin";
            dept.DeptName = "Store";

            Employee emp = new Employee();
            emp.EmpName = "Ron";
            emp.EmpAge = 30;

            IList<Employee> empList = new List<Employee>();
            empList.Add(emp);
            dept.Employees = empList;
            emp.Dept = dept;

            IRepository<Dept> rDept = new Repository<Dept>();
            rDept.SaveOrUpdate(dept);
        }
        catch (Exception ex)
        {
            Console.WriteLine(ex.Message);
        }

我在这里遇到错误

InnerException = {无效的列名'Dept_id'."} 消息=无法插入:[Project.Model.Employee] [SQL:插入[雇员](EmpName，EmpAge，DeptId，Dept_id)值(?，?，?，?)；选择SCOPE_IDENTITY()]"

InnerException = {"Invalid column name 'Dept_id'."} Message = "could not insert: [Project.Model.Employee][SQL: INSERT INTO [Employee] (EmpName, EmpAge, DeptId, Dept_id) VALUES (?, ?, ?, ?); select SCOPE_IDENTITY()]"

推荐答案

Mattias的答案几乎是正确的，但是ForeignKey用于生成模式.请尝试以下映射.此外，您还具有与CascadeAll映射的Employees集合.如果您删除部门，这将删除员工记录，这可能是不希望的.

Mattias' answer is almost right, but ForeignKey is used for schema generation. Try the below mapping instead. Also, you have the Employees collection mapped with CascadeAll. This will delete employee records if you delete a department, which is probably not desirable.

public class DeptMapping : ClassMap<Dept>
    { 
        public DeptMapping() 
        {
            Id(x => x.Id); 
            Map(x => x.DeptName); 
            Map(x => x.DeptLocation); 
            HasMany(x => x.Employees).KeyColumn("DeptId").Inverse().Cascade.All(); 
        } 
    }

public class EmployeeMapping : ClassMap<Employee>
{ 
    public EmployeeMapping() 
    { 
        Id(x => x.Id); 
        Map(x => x.EmpName); 
        Map(x => x.EmpAge); 
        Map(x => x.DeptId); 
        References(x => x.Dept, "DeptId").Cascade.None(); 
   } 
}

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