无法使用具有Master-detail关系的EF插入数据 [英] Can't insert data to with EF with Master-detail relationship

问题描述

假设我有2个表：

Person(pid, ....)   //Pid is identify colum as primary key
Student(pid, Student_No,...)   //pid is foreign key from Person, pid is a primary key too.

然后使用EF生成实体模型。因此尝试使用以下代码插入新数据：

Then use EF to generate entity model. THen try to insert new data with following code:

 Person person = new Person()
           { FirstName = "FirstName", LastName= "LastName", ... };
 Student student = new Student(){Student_No="001", ...};
 Student.Person = person;
 mycontext.Students.AddObject(student);
 mycontext.SaveChanges();

然后我收到错误：
参考代码中的依赖属性映射到一个商店生成列。列：'pid'。

Then I get error as: A dependent property in a ReferentialConstraint is mapped to a store-generated column. Column: 'pid'.

如何解决？

修改代码如下：

 Person person = new Person(){ FirstName = "FirstName", LastName= "LastName", ... };
  mycontext.People.AddObject(person);
  mycontext.SaveChanges();

 Student student = new Student(){Student_No="001", Person = person,  ...};
 // or  Student student = new Student(){Student_No="001", pid= person.pid,  ...};
 mycontext.Students.AddObject(student);
 mycontext.SaveChanges();

然后我可以插入人，但对于学生，仍然会收到相同的错误。在EDM中检查学生实体pid属性：storegeneratedPatteren = None。很混乱

then I was able to insert for person, but for Student, still get same error. Check Student entity pid property in EDM: storegeneratedPatteren = None. Quite confused.

推荐答案

听起来像你有一个学生是一种人。如果这是真的，那么您应该考虑使用每种类型的继承 。这里的详细信息 http://msdn.microsoft.com/en-us/library/bb738685 .aspx

Sounds like you have a student which is a type of person. If this is true then you should consider using Table-per-type Inheritance. Details here http://msdn.microsoft.com/en-us/library/bb738685.aspx

已编辑：

如果您选择不使用继承，则需要先插入该人：

If you choose not to use inheritance you need to insert the person first:

 Person person = new Person()
           { FirstName = "FirstName", LastName= "LastName", ... };

 mycontext.Person.AddObject(person);
 mycontext.SaveChanges();

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