nhibernate - Fluent NHibernate 多对一映射

Question

我是 Hibernate 世界的新手。这可能是一个愚蠢的问题，但我无法解决它。我正在测试表的多对一关系并尝试插入记录。我有一个部门表和员工表。员工和部门在这里是多对一的关系。我正在使用 Fluent NHibernate 添加记录。下面的所有代码。请帮忙

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);
        }

在这里我收到错误

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()]"

Answer 1

Mattias 的回答几乎是正确的，但 ForeignKey 用于模式生成。请尝试以下映射。此外，您还使用 CascadeAll 映射了Employees 集合。如果您删除一个部门，这将删除员工记录，这可能是不可取的。

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(); 
   } 
}