Question

我正在尝试在nhibernate中映射一个简单的数据结构

表格

Employees
employeeID int
username varchar(30)
departmentID int

Departments
departmentID int
deptName varchar(50)

我的部门映射是这样的：

public class DepartmentMap: ClassMap<Department>
{
    public DepartmentMap()
    {
        Id(m => m.DepartmentID).Column("departmentID");
        Map(m => m.DepartmentName).Column("deptName").Length(50);

        HasMany(m => m.Employees);

        Table("Departments");
    }
}

...和员工映射

public class EmployeeMap : ClassMap<Employee>
{
    public EmployeeMap()
    {
        Id(x => x.EmployeeID, "employeeID");
        Map(x => x.UserName, "username").Length(30);

        References<Department>(x => x.Department, "departmentID");

        Table("Employees");
    }
}

我正在尝试遍历部门并从每个部门拉出所有员工：

foreach (var i in _directoryData.DepartmentCollection)
{
    foreach (var e in i.Employees)
    {
        Debug.WriteLine(i.DepartmentName + " " + e.UserName);
    }
}

这给了我一个错误，声明“Invalid column name 'Department_id'.”...并且在生成的查询中它也使用了department_id。当我只是循环部门并输出部门名称时，它可以正常工作。

知道我缺少什么来获取departmentID的正确列名？以下是我的模型对象：

public class Department
{
    public virtual int DepartmentID { get; set; }
    public virtual string DepartmentName { get; set; }

    public virtual ICollection<Employee> Employees { get; set; }
}

public class Employee : PersistentEntity
{
    public virtual int EmployeeID { get; set; }
    public virtual string UserName { get; set; }

    public virtual Department Department { get; set; }
}

Answer 1

您可以：创建一个Fluent NHibernate 约定，以便将HasMany“外键”创建为<'Name'>ID。

或更改部门映射：

 HasMany(m => m.Employees).KeyColumns.Add("DepartmentID")

Answer 2

您需要指定键列。

HasMany(m => m.Employees).KeyColumn("DepartmentId");

Answer 3

您需要在HasMany声明中使用KeyColumn方法，如documentation

中所述

流畅的NHibernate HasMany外键映射问题

3 个答案: