entity-framework - Entity Framework 删除语句与引用约束冲突

Question

我有两个表 Employee (n) 和 Store (1)，它们具有 n:1 关系。

Employee 具有外键 idStore，它是来自 Store 的主键。

以下是我尝试从Employee删除行的方法:

public void deleteEmployee(int idEmployee)
{
   MyEntities pe = new MyEntities();
   try
   {
      var firstQuery = from e in pe.Employees
                       where e.idEmployee == idEmployee
                       select e;
      string findIdStore = firstQuery.First().StoreReference.EntityKey.EntityKeyValues[0].Value.ToString();
      int idStore = Int32.Parse(findIdStore);
      Store r = pe.Stores.First(c => c.idStore == idStore);
      r.Employees.Remove(firstQuery.First());
      pe.DeleteObject(firstQuery.First());
      pe.SaveChanges();
   }
   catch (Exception ex)
   {
      return;
   }
}

而且，我仍然收到删除语句与引用约束冲突的错误。

完整的错误在这里:

The DELETE statement conflicted with the REFERENCE constraint "FK_Bill_Employee". The conflict occurred in database "myDatabase", table "dbo.Bill", column 'idEmployeeMember'.
The statement has been terminated.

Answer 1

你不能找到并删除该员工吗？

public void deleteEmployee(int idEmployee)
{
   using(MyEntities pe = new MyEntities())
   {
      var emmployeeToDelete = pe.Employees.FirstOrDefault(e => e.idEmployee == idEmployee);

      if(employeeToDelete != null)
      {
          pe.DeleteObject(employeeToDelete);
          pe.SaveChanges();
      }
   }
}

我认为你不需要做更多的事情，真的......

下次当您加载该员工所属的这个特定商店时，该员工将不再位于该商店的员工集合中 - 无需进行任何困惑的手动删除或任何操作......