Sql 实体框架-选择可为空的联接属性

我的表结构如下所示：

Account
 AccountId
 LoginName
 EmployeeId - nullable
Employee
  FirstName,
  SecondName,
  etc..

我有疑问：

   var data = from o in _accountRepository.AsQueryableWithIncludes(x => x.Employee, x => x.Permissions)
               select new AccountGridVM
               {
                   AccountId = o.AccountId,
                   EmployeeFirstName = o.EmployeeId == null ? String.Empty: o.Employee.FirstName,
                   LoginName = o.LoginName,
                   Permissions = o.Permissions.Select(s => s.NameCZ)
               };
    return View(new GridModel { Data = data });

我的问题是EmployeeFirstName中的tenar运算符，实体框架总是只获取帐户，它分配了employeeId，但我需要获取所有帐户

如果删除EmployeeFirstName属性，则ef获取所有行

问题在哪里

---

谢谢，问题解决了。我在绘制地图时出错了

  //bad
  HasRequired(x => x.Employee).WithMany().HasForeignKey(x => x.EmployeeId); // inner join

  //good
  HasOptional(x => x.Employee).WithMany().HasForeignKey(x => x.EmployeeId); // left join

---

您是否尝试了

o.EmployeeId==null

而不是

o.EmployeeId==null

？是的，尝试o.EmployeeId.HasValue，o.EmployeeId==null，o.EmployeeId=null