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EF4：映射到一個 「額外字段」 表

2011-03-22 53 views
0

我有兩個表：EF4：映射到一個 「額外字段」 表

TICKET

  • GUID（PK）
  • 有沒有涉及到這個問題
其他列

TICKET_PROPERTIES

  • GUID（partial PK，FK到TICKET.GUID）
  • FIELDNAME（局部PK）
  • fieldValue方法

如果我有這些門票記載：

  • {GUID = 「my_ticket」}
  • { GUID = 「my_ticket_2」}

然後我可能有一些TICKET_PROPERTIES記錄，如：

  • {GUID = 「my_ticket」，FIELDNAME = 「FIELDA」，fieldValue方法= 「值的」}
  • {GUID = 「my_ticket」，FIELDNAME = 「FieldB」，fieldValue方法= 「foo」 的}
  • {GUID = 「my_ticket」，FIELDNAME = 「FieldC」，fieldValue方法= 「酒吧」}
  • {GUID = 「my_ticket_2」，FIELDNAME = 「FieldC」，fieldValue方法= 「等等」}
  • {GUID =「my_ticket_2 「，FIELDNAME =」FieldD「，FIELDVALUE =」data「}

如您所見，此TICKET_PROPERTIES表用作TICKET記錄可以選擇具有的字段的「額外字段」表。 TICKET可能並不總是具有與FIELDNAME =「FieldA」相關聯的TICKET_PROPERTIES記錄，但有時他們會這樣做。

如果我想在此EDMX文件的TICKET類中添加FieldA屬性，我該怎麼做？ 這將是很好，如果這樣的屬性可以建立一個where條件成像這樣生成的查詢：

MINE_EF_TestContext ctx = new MINE_EF_TestContext(); 
var someTickets = ctx.TICKET.Where(t => t.FieldA == "value a");

我想可以添加多個屬性這樣。例如，我可能希望能夠添加一個FieldB屬性。

我的EDMX：

<edmx:Edmx Version="2.0" xmlns:edmx="http://schemas.microsoft.com/ado/2008/10/edmx"> 
<edmx:Runtime> 
<edmx:StorageModels> 
<Schema Namespace="MINE_EF_Test.Store" Alias="Self" Provider="EFOracleProvider" ProviderManifestToken="11g" xmlns:store="http://schemas.microsoft.com/ado/2007/12/edm/EntityStoreSchemaGenerator" xmlns="http://schemas.microsoft.com/ado/2009/02/edm/ssdl"> 
    <EntityContainer Name="MINE_EF_TestStoreContainer"> 
    <EntitySet Name="TICKET" EntityType="MINE_EF_Test.Store.TICKET" store:Type="Tables" /> 
    <EntitySet Name="TICKET_PROPERTIES" EntityType="MINE_EF_Test.Store.TICKET_PROPERTIES" store:Type="Tables" /> 
    <AssociationSet Name="TICKET_PROPERTIES_TICKET_FK" Association="MINE_EF_Test.Store.TICKET_PROPERTIES_TICKET_FK"> 
     <End Role="TICKET" EntitySet="TICKET" /> 
     <End Role="TICKET_PROPERTIES" EntitySet="TICKET_PROPERTIES" /> 
    </AssociationSet> 
    </EntityContainer> 
    <EntityType Name="TICKET"> 
    <Key> 
     <PropertyRef Name="GUID" /> 
    </Key> 
    <Property Name="GUID" Type="varchar2" Nullable="false" MaxLength="36" /> 
    </EntityType> 
    <EntityType Name="TICKET_PROPERTIES"> 
    <Key> 
     <PropertyRef Name="FIELDNAME" /> 
     <PropertyRef Name="GUID" /> 
    </Key> 
    <Property Name="FIELDNAME" Type="varchar2" Nullable="false" MaxLength="40" /> 
    <Property Name="FIELDVALUE" Type="varchar2" Nullable="false" MaxLength="1000" /> 
    <Property Name="GUID" Type="varchar2" Nullable="false" MaxLength="36" /> 
    </EntityType> 
    <Association Name="TICKET_PROPERTIES_TICKET_FK"> 
    <End Role="TICKET" Type="MINE_EF_Test.Store.TICKET" Multiplicity="1" /> 
    <End Role="TICKET_PROPERTIES" Type="MINE_EF_Test.Store.TICKET_PROPERTIES" Multiplicity="*" /> 
    <ReferentialConstraint> 
     <Principal Role="TICKET"> 
     <PropertyRef Name="GUID" /> 
     </Principal> 
     <Dependent Role="TICKET_PROPERTIES"> 
     <PropertyRef Name="GUID" /> 
     </Dependent> 
    </ReferentialConstraint> 
    </Association> 
    <Association Name="TICKET_PROPERTIES_TICKET_FK_POC"> 
    <End Role="TICKET" Type="MINE_EF_Test.Store.TICKET" Multiplicity="0..1" /> 
    <End Role="TICKET_PROPERTIES" Type="MINE_EF_Test.Store.TICKET_PROPERTIES" Multiplicity="1" /> 
    <ReferentialConstraint> 
     <Principal Role="TICKET_PROPERTIES"> 
     <PropertyRef Name="GUID" /> 
     </Principal> 
     <Dependent Role="TICKET"> 
     <PropertyRef Name="GUID" /> 
     </Dependent> 
    </ReferentialConstraint> 
    </Association> 
</Schema> 
</edmx:StorageModels> 
<edmx:ConceptualModels> 
<Schema Namespace="MINE_EF_Test" Alias="Self" xmlns:annotation="http://schemas.microsoft.com/ado/2009/02/edm/annotation" xmlns="http://schemas.microsoft.com/ado/2008/09/edm"> 
    <EntityContainer Name="MINE_EF_TestContext" annotation:LazyLoadingEnabled="true"> 
    <EntitySet Name="TICKET" EntityType="MINE_EF_Test.TICKET" /> 
    <EntitySet Name="TICKET_PROPERTIES" EntityType="MINE_EF_Test.TICKET_PROPERTIES" /> 
    <AssociationSet Name="TICKET_PROPERTIES_TICKET_FK" Association="MINE_EF_Test.TICKET_PROPERTIES_TICKET_FK"> 
     <End Role="TICKET" EntitySet="TICKET" /> 
     <End Role="TICKET_PROPERTIES" EntitySet="TICKET_PROPERTIES" /> 
    </AssociationSet> 
    </EntityContainer> 
    <EntityType Name="TICKET"> 
    <Key> 
     <PropertyRef Name="GUID" /> 
    </Key> 
    <Property Name="GUID" Type="String" Nullable="false" MaxLength="36" Unicode="false" FixedLength="false" /> 
    <NavigationProperty Name="TICKET_PROPERTIES" Relationship="MINE_EF_Test.TICKET_PROPERTIES_TICKET_FK" FromRole="TICKET" ToRole="TICKET_PROPERTIES" /> 
    </EntityType> 
    <EntityType Name="TICKET_PROPERTIES"> 
    <Key> 
     <PropertyRef Name="FIELDNAME" /> 
     <PropertyRef Name="GUID" /> 
    </Key> 
    <Property Name="FIELDNAME" Type="String" Nullable="false" MaxLength="40" Unicode="false" FixedLength="false" /> 
    <Property Name="FIELDVALUE" Type="String" Nullable="false" MaxLength="1000" Unicode="false" FixedLength="false" /> 
    <Property Name="GUID" Type="String" Nullable="false" MaxLength="36" Unicode="false" FixedLength="false" /> 
    <NavigationProperty Name="TICKET" Relationship="MINE_EF_Test.TICKET_PROPERTIES_TICKET_FK" FromRole="TICKET_PROPERTIES" ToRole="TICKET" /> 
    </EntityType> 
    <Association Name="TICKET_PROPERTIES_TICKET_FK"> 
    <End Role="TICKET" Type="MINE_EF_Test.TICKET" Multiplicity="1" /> 
    <End Role="TICKET_PROPERTIES" Type="MINE_EF_Test.TICKET_PROPERTIES" Multiplicity="*" /> 
    <ReferentialConstraint> 
     <Principal Role="TICKET"> 
     <PropertyRef Name="GUID" /> 
     </Principal> 
     <Dependent Role="TICKET_PROPERTIES"> 
     <PropertyRef Name="GUID" /> 
     </Dependent> 
    </ReferentialConstraint> 
    </Association> 
</Schema> 
</edmx:ConceptualModels> 
<edmx:Mappings> 
<Mapping Space="C-S" xmlns="http://schemas.microsoft.com/ado/2008/09/mapping/cs"> 
    <EntityContainerMapping StorageEntityContainer="MINE_EF_TestStoreContainer" CdmEntityContainer="MINE_EF_TestContext"> 
    <EntitySetMapping Name="TICKET"> 
     <EntityTypeMapping TypeName="MINE_EF_Test.TICKET"> 
     <MappingFragment StoreEntitySet="TICKET"> 
      <ScalarProperty Name="GUID" ColumnName="GUID" /> 
      </MappingFragment> 
     </EntityTypeMapping> 
    </EntitySetMapping> 
    <EntitySetMapping Name="TICKET_PROPERTIES"> 
     <EntityTypeMapping TypeName="MINE_EF_Test.TICKET_PROPERTIES"> 
     <MappingFragment StoreEntitySet="TICKET_PROPERTIES"> 
      <ScalarProperty Name="FIELDNAME" ColumnName="FIELDNAME" /> 
      <ScalarProperty Name="FIELDVALUE" ColumnName="FIELDVALUE" /> 
      <ScalarProperty Name="GUID" ColumnName="GUID" /> 
     </MappingFragment> 
     </EntityTypeMapping> 
    </EntitySetMapping> 
    </EntityContainerMapping> 
</Mapping> 
</edmx:Mappings> 
</edmx:Runtime> 
<edmx:Designer xmlns="http://schemas.microsoft.com/ado/2008/10/edmx"> 
<Connection><DesignerInfoPropertySet><DesignerProperty Name="MetadataArtifactProcessing" Value="EmbedInOutputAssembly" /></DesignerInfoPropertySet></Connection> 
<edmx:Options /> 
<edmx:Diagrams > 
     <Diagram Name="MINE_EF_Test" ZoomLevel="96"> 
     <EntityTypeShape EntityType="MINE_EF_Test.TICKET" Width="1.5" PointX="0.75" PointY="1.125" Height="1.4033821614583335" IsExpanded="true" /> 
     <EntityTypeShape EntityType="MINE_EF_Test.TICKET_PROPERTIES" Width="1.5" PointX="2.75" PointY="1.25" Height="1.787985026041667" IsExpanded="true" /> 
     <AssociationConnector Association="MINE_EF_Test.TICKET_PROPERTIES_TICKET_FK" ManuallyRouted="false"> 
      <ConnectorPoint PointX="2.25" PointY="1.8891910807291668" /> 
      <ConnectorPoint PointX="2.75" PointY="1.8891910807291668" /> 
     </AssociationConnector> 
     </Diagram> 
    </edmx:Diagrams> 
</edmx:Designer></edmx:Edmx>

來源

2011-03-22 Joel

回答

0

當前EF版本不提供關聯表父實體屬性映射記錄。此外，這種情況需要動態屬性，因爲您可以使用不同名稱的不同數量的相關記錄。

您必須使用這種方法：

MINE_EF_TestContext ctx = new MINE_EF_TestContext(); 
var someTickets = from t in ctx.Tickets 
        join p in ctx.Properties on t.Guid equals p.Guid 
        where p.FieldName == "FieldA" && p.FieldValue == "value a" 
        select t;

來源

2011-03-22 22:12:51

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