与beta 2的EDM映射问题 [英] EDM mapping problem with beta 2

问题描述

我有四张桌子Child，Toy，Food和Child2Entity。我希望通过关联表将孩子，糖果（1对多）和玩具（1对多）联系起来。
所有玩具的EntityType = 1，糖果的EntityType = 2。来自DB的孩子我希望根据EntityType获得他所有相关的糖果和玩具，例如，如果我选择从EntityType = 1中检索孩子和他的相关实体，我将期望得到一个特定的孩子玩具。
我也希望有可能在DB中保存一个孩子和一个相关实体（玩具或糖果）。
请注意Child和Child2Entity之间只有一个关联。儿童2实体代码片段：

< EntityType Name =" Child2Entity"> 
< Key> 
< PropertyRef Name =" ChildID" /> 
< PropertyRef Name =" EntityID" /> 
< PropertyRef Name =" EntityTypeID" /> 
< / Key> 
< Property Name =" ChildID"类型=" INT"可空= QUOT假QUOT; /> 
< Property Name =" EntityID"类型=" INT"可空= QUOT假QUOT; /> 
< Property Name =" EntityTypeID"类型=" INT"可空= QUOT假QUOT; /> 
< / EntityType> 

儿童代码段：

< EntityType Name = "儿童"> 
< Key> 
< PropertyRef Name =" ID" /> 
< / Key> 
< Property Name =" ID"类型=" INT"可空= QUOT假QUOT; /> 
< Property Name =" Name"类型=" nvarchar的"的MaxLength = QUOT; 50" /> 
< Property Name =" Address"类型="为nvarchar（最大）" /> 
< / EntityType> 

玩具代码段：

< EntityType Name =" Toy"> 
< Key> 
< PropertyRef Name =" ID" /> 
< / Key> 
< Property Name =" ID"类型=" INT"可空= QUOT假QUOT; /> 
< Property Name =" Name"类型=" nvarchar的"的MaxLength = QUOT; 50" /> 
< / EntityType> 

糖果代码段：

< EntityType Name =" Candy" > 
< Key> 
< PropertyRef Name =" ID" /> 
< / Key> 
< Property Name =" ID"类型=" INT"可空= QUOT假QUOT; /> 
< Property Name =" Name"类型=" nvarchar的"的MaxLength = QUOT; 50" /> 
< Property Name =" Color"类型=" INT" /> 
< / EntityType> 

Child和Child2Entity之间的关联：

< Association Name =" FK_Child2Entity_Child"> ; 
< End Role =" Child"类型=" AppBlockTestModel.Store.Child"多重= QUOT 1 QUOT; /> 
< End Role =" Child2Entity"类型=" AppBlockTestModel.Store.Child2Entity"多重= QUOT * QUOT; /> 
< ReferentialConstraint> 
< Principal Role =" Child"> 
< PropertyRef Name =" ID" /> 
< / Principal> 
< Dependent Role =" Child2Entity"> 
< PropertyRef Name =" ChildID" /> 
< / Dependent> 
< / ReferentialConstraint> 
< / Association> 

解决方案

嗨majhul，

我正在移动这个帖子到EF预发布论坛，因为有更多关于beta2的专家。
你会在那个论坛得到更好的答案。

最诚挚的问候是刘志春

I have four tables Child, Toy, Food and Child2Entity. I want to associate to a child, candies (1 to many) and toys (1 to many) by the association table.
All the toys have EntityType=1 and Candies have EntityType=2.
When Getting a child from DB I want to get all his related candies and toys according to the EntityType
for instance if i choose to retrieve a child and his related Entities from EntityType=1 i will expect to get a certain child with all his toys.
I also wish to have the possibility to save in DB a child and a related entity (a toy or a candy).
Please pay attention that there is only one association between Child and  Child2Entity.

 
Child2Entity code snippet:

<EntityType Name="Child2Entity">
          <Key>
            <PropertyRef Name="ChildID" />
            <PropertyRef Name="EntityID" />
            <PropertyRef Name="EntityTypeID" />
          </Key>
          <Property Name="ChildID" Type="int" Nullable="false" />
          <Property Name="EntityID" Type="int" Nullable="false" />
          <Property Name="EntityTypeID" Type="int" Nullable="false" />
        </EntityType>

Child code snippet:

<EntityType Name="Child">
          <Key>
            <PropertyRef Name="ID" />
          </Key>
          <Property Name="ID" Type="int" Nullable="false" />
          <Property Name="Name" Type="nvarchar" MaxLength="50" />
          <Property Name="Address" Type="nvarchar(max)" />
        </EntityType>

Toy code snippet:

<EntityType Name="Toy">
          <Key>
            <PropertyRef Name="ID" />
          </Key>
          <Property Name="ID" Type="int" Nullable="false" />
          <Property Name="Name" Type="nvarchar" MaxLength="50" />
</EntityType>

Candy code snippet:

<EntityType Name="Candy">
          <Key>
            <PropertyRef Name="ID" />
          </Key>
          <Property Name="ID" Type="int" Nullable="false" />
          <Property Name="Name" Type="nvarchar" MaxLength="50" />
          <Property Name="Color" Type="int" />
        </EntityType>

Association between Child and Child2Entity:

<Association Name="FK_Child2Entity_Child">
          <End Role="Child" Type="AppBlockTestModel.Store.Child" Multiplicity="1" />
          <End Role="Child2Entity" Type="AppBlockTestModel.Store.Child2Entity" Multiplicity="*" />
          <ReferentialConstraint>
            <Principal Role="Child">
              <PropertyRef Name="ID" />
            </Principal>
            <Dependent Role="Child2Entity">
              <PropertyRef Name="ChildID" />
            </Dependent>
          </ReferentialConstraint>
        </Association>

解决方案

Hi majhul,

I'm moving this thread to EF pre-release forum, since there are more experts on beta2.
You'll get better answer in that forum.


Best Regards
Yichun Feng

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