从子实体的属性过滤基础实体 [英] Filter base entity from child entities' properties

问题描述

我一直在寻找一个解决方案几天。

I have been looking for a solution for days now.

我的应用程序中有八个实体，一个基数和七个从该基础实体继承的实体。一些子实体具有相同的属性。

I have eight entities in my application, a base and seven entities that inherits from this base entity. Some of the child entities have same properties.

public class LogEntry(){
    public int LogEntryId{get;set;}
    public string ...
}

public class TestEntry : LogEntry{
   ....
   public string SomeProperty{get;set;} //SomePropertyThatIsNotInBaseClass
   ....
}
public class XEntry : LogEntry{
   ....
   public string SomeProperty{get; set;}
   ....
}

我试图过滤这个SomeProperty的基础实体。我正在尝试一个查询，如

I am trying to filter base entity by this SomeProperty. I am trying to a query like

var value = Db.LogEntry.Where(i=>i.SomePropery == "some string");

不允许。我只能通过

IQueryable<LogEntry> first = Db.LogEntry.OfType<TestEntry>.Where(i=>i.SomeProperty == "...");
IQueryable<LogEntry> second = Db.LogEntry.OfType<XEntry>.Where(i=>i.SomeProperty == "...");
...

最后连接它们。有比这种方法更聪明的做法吗？扩展方法等...

And concatenate them at the end. Is there more clever way to do than this method? Extension methods etc...

任何帮助将不胜感激。

推荐答案

p> 修改

更仔细地看你的例子，我不认为你想做的是可能的。如果您正在针对BASE实体类型编写查询，则只能查询基类型中定义的字段。

Looking at your example more closely, I don't think what you are trying to do is possible. If you are writing a query against the BASE entity type, then you can only query fields that are defined in the base type.

由于LogEntry中未定义SomeProperty ，你不能写这个查询：

Since "SomeProperty" is not defined in LogEntry, you cannot write this query:

var logEntries = db.LogEntry.Where(r => r.SomeProperty == "foo");

由于LogEntry类中未定义SomeProperty。

Because SomeProperty is not defined in the LogEntry class.

如果要针对基类编写查询，则需要执行以下操作：

If you want to write queries against the base class then you need to do something like the following:

public class TPTContext : DbContext
{
    public TPTContext() : base("name=TPT")
    { }

    public DbSet<BillingDetail> BillingDetails { get; set; }
}

public abstract class BillingDetail
{
    public int BillingDetailId { get; set; }
    public string Owner { get; set; }
    public string Number { get; set; }
}

[Table("BankAccounts")]
public class BankAccount : BillingDetail
{
    public string BankName { get; set; }
    public string Swift { get; set; }
}

[Table("CreditCards")]
public class CreditCard : BillingDetail
{
    public int CardType { get; set; }
    public string ExpiryMonth { get; set; }
    public string ExpiryYear { get; set; }
}

我对基类编写了以下查询：

I wrote the following query against the base class:

TPTContext db = new TPTContext();

var allAccounts = db.BillingDetails.Where(b => b.Owner == "boran");
var bankAccounts = allAccounts.OfType<BankAccount>();
var creditCards = allAccounts.OfType<CreditCard>();

一切似乎都适用于我。

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