视图和组合键 [英] Views and composite key

问题描述

我有一个无法修改数据库的场景

有一个视图包含三个不同的表ID和其他字段。

I have a scenario where the db cannot be modified at all
There is a View that contains three different table ids and other fields.

为了从视图中读取数据，我必须声明一个PK（因为它是readonly，这不应该是一个要求）。

我试图以这种方式建模，但是CTP4 fais，错误"键表达式无效。"

In order to read the data from the view, I have to declare a PK (as it is readonly, this should not be a requirement).
I tried to model the key this way, but CTP4 fais with the error "Key expression is not valid."

modelBuilder.Entity<Stocked>().HasKey(
   p => new
   {
     ArticleId = p.Article.Id,
     WarehouseId = p.Warehouse.Id,
     BatchId = p.Batch.Id,
   });

问题是我的实体不包含"ID"作为int但是对另一个实体的引用所以我没有要放入lambda的属性。

The problem is that my entity does not contain the "ID" as int but the reference to another entity so I have no properties to put in the lambda.

问题：

1.是否有另一种方式来声明PK（或完全避免它）？

2.对于下一个CTP / beta / RTM，我坚信不应该只读取（仅限AKA选择）数据的PK。我错过了什么吗？

Questions:
1. Is there an alternative way to declare the PK (or to avoid it at all)?
2. For the next CTP/beta/RTM I strongly believe there should not be the requirement for PKs for readonly (AKA select-only) data. Am I missing something?

谢谢

推荐答案

嗨Raffaele，

Hi Raffaele,

Code First目前仅限支持映射到读/写表&观点。 EF一般支持映射到只读查看数据，但在下一版本的Code First中不支持，我们计划在将来支持这一点。

Code First currently only supports mapping to read/write tables & views. EF in general does support mapping to readonly view data but this won't be supported in Code First in the next release, we do plan to support this in the future.

最好的选择是是使用底层上下文对视图运行查询：

The best option would be to use the underlying context to run a query against the view:

public class MyContext : DbContext
{
  ...

  public IEnumerable<Stocked> GetStocked()
  {
    return this.ObjectContext.ExecuteStoreQuery<Stocked>("SELECT * FROM dbo.StockedView");
  }
}

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