Question

我有点陷入困境，我在下面的实体框架映射出错了。我所做的是：

a）创建了一个Sqlite数据库（见下文，注意Sqlite不允许FK约束） b）创建一个空白的实体数据模式＆amp;然后从数据库中创建模型 c）然后问题是尝试添加Model关联，以便它获取并使用我在USAGES表中的数据库中创建的“ProcessNameId”列。我一直在尝试使用GUI表映射窗格来执行此操作，但它似乎不太直观。

问题 - 我收到以下错误：

Error 3 
Error 3021: Problem in mapping fragments starting at line 85:
Each of the following columns in table Usages is mapped to multiple conceptual side properties:

Usages.ProcessNameId is mapped to <ProcessNameUsage.ProcessName.Id,  ProcessNameUsage.Usage.Id>
Error   4
Error 3025: Problem in mapping fragments starting at line 85:
Must specify mapping for all key properties (Usages.Id) of table Usages.

问题 - 所以问题是我需要对XML进行哪些更改才能使关联正常工作？

SQL

CREATE TABLE "ProcessNames" (
    "Id" INTEGER PRIMARY KEY  AUTOINCREMENT NOT NULL , 
    "Name" VARCHAR NOT NULL  UNIQUE
)

CREATE TABLE "Usages" (
    "Id" INTEGER PRIMARY KEY  AUTOINCREMENT  NOT NULL , 
    "ProcessNameId" INTEGER NOT NULL , 
    "Amount" INTEGER NOT NULL , 
    "Datetime" DATETIME NOT NULL 
)

模型配置

<?xml version="1.0" encoding="utf-8"?>
<edmx:Edmx Version="2.0" xmlns:edmx="http://schemas.microsoft.com/ado/2008/10/edmx">
  <!-- EF Runtime content -->
  <edmx:Runtime>
    <!-- SSDL content -->
    <edmx:StorageModels>
    <Schema Namespace="Model1.Store" Alias="Self" Provider="System.Data.SQLite" ProviderManifestToken="ISO8601" xmlns:store="http://schemas.microsoft.com/ado/2007/12/edm/EntityStoreSchemaGenerator" xmlns="http://schemas.microsoft.com/ado/2009/02/edm/ssdl">
        <EntityContainer Name="Model1StoreContainer">
          <EntitySet Name="ProcessNames" EntityType="Model1.Store.ProcessNames" store:Type="Tables" />
          <EntitySet Name="Usages" EntityType="Model1.Store.Usages" store:Type="Tables" />
        </EntityContainer>
        <EntityType Name="ProcessNames">
          <Key>
            <PropertyRef Name="Id" />
          </Key>
          <Property Name="Id" Type="integer" Nullable="false" StoreGeneratedPattern="Identity" />
          <Property Name="Name" Type="nvarchar" Nullable="false" />
        </EntityType>
        <EntityType Name="Usages">
          <Key>
            <PropertyRef Name="Id" />
          </Key>
          <Property Name="Id" Type="integer" Nullable="false" StoreGeneratedPattern="Identity" />
          <Property Name="ProcessNameId" Type="integer" Nullable="false" />
          <Property Name="Amount" Type="integer" Nullable="false" />
          <Property Name="Datetime" Type="datetime" Nullable="false" />
        </EntityType>
      </Schema></edmx:StorageModels>
    <!-- CSDL content -->
    <edmx:ConceptualModels>
      <Schema xmlns="http://schemas.microsoft.com/ado/2008/09/edm" xmlns:cg="http://schemas.microsoft.com/ado/2006/04/codegeneration" xmlns:store="http://schemas.microsoft.com/ado/2007/12/edm/EntityStoreSchemaGenerator" Namespace="Model1" Alias="Self" xmlns:annotation="http://schemas.microsoft.com/ado/2009/02/edm/annotation">
        <EntityContainer Name="Model1Container" annotation:LazyLoadingEnabled="true">
          <EntitySet Name="ProcessNames" EntityType="Model1.ProcessName" />
          <EntitySet Name="Usages" EntityType="Model1.Usage" />
          <AssociationSet Name="ProcessNameUsage" Association="Model1.ProcessNameUsage">
            <End Role="ProcessName" EntitySet="ProcessNames" />
            <End Role="Usage" EntitySet="Usages" />
          </AssociationSet>
        </EntityContainer>
        <EntityType Name="ProcessName">
          <Key>
            <PropertyRef Name="Id" />
          </Key>
          <Property Type="Int64" Name="Id" Nullable="false" annotation:StoreGeneratedPattern="Identity" />
          <Property Type="String" Name="Name" Nullable="false" MaxLength="2147483647" FixedLength="false" Unicode="true" />
          <NavigationProperty Name="Usages" Relationship="Model1.ProcessNameUsage" FromRole="ProcessName" ToRole="Usage" />
        </EntityType>
        <EntityType Name="Usage">
          <Key>
            <PropertyRef Name="Id" />
          </Key>
          <Property Type="Int64" Name="Id" Nullable="false" annotation:StoreGeneratedPattern="Identity" />
          <Property Type="Int64" Name="ProcessNameId" Nullable="false" />
          <Property Type="Int64" Name="Amount" Nullable="false" />
          <Property Type="DateTime" Name="Datetime" Nullable="false" />
          <NavigationProperty Name="ProcessName" Relationship="Model1.ProcessNameUsage" FromRole="Usage" ToRole="ProcessName" />
        </EntityType>
        <Association Name="ProcessNameUsage">
          <End Type="Model1.ProcessName" Role="ProcessName" Multiplicity="1" />
          <End Type="Model1.Usage" Role="Usage" Multiplicity="*" />
        </Association>
      </Schema>
    </edmx:ConceptualModels>
    <!-- C-S mapping content -->
    <edmx:Mappings>
    <Mapping Space="C-S" xmlns="http://schemas.microsoft.com/ado/2008/09/mapping/cs">
  <EntityContainerMapping StorageEntityContainer="Model1StoreContainer" CdmEntityContainer="Model1Container">
          <EntitySetMapping Name="ProcessNames">
            <EntityTypeMapping TypeName="Model1.ProcessName">
              <MappingFragment StoreEntitySet="ProcessNames">
                <ScalarProperty Name="Name" ColumnName="Name" />
                <ScalarProperty Name="Id" ColumnName="Id" />
              </MappingFragment>
            </EntityTypeMapping>
          </EntitySetMapping>
          <EntitySetMapping Name="Usages">
            <EntityTypeMapping TypeName="Model1.Usage">
              <MappingFragment StoreEntitySet="Usages">
                <ScalarProperty Name="Datetime" ColumnName="Datetime" />
                <ScalarProperty Name="Amount" ColumnName="Amount" />
                <ScalarProperty Name="ProcessNameId" ColumnName="ProcessNameId" />
                <ScalarProperty Name="Id" ColumnName="Id" />
              </MappingFragment>
            </EntityTypeMapping>
          </EntitySetMapping>
          <AssociationSetMapping Name="ProcessNameUsage" TypeName="Model1.ProcessNameUsage" StoreEntitySet="Usages">
            <EndProperty Name="ProcessName">
              <ScalarProperty Name="Id" ColumnName="ProcessNameId" />
            </EndProperty>
            <EndProperty Name="Usage">
              <ScalarProperty Name="Id" ColumnName="ProcessNameId" />
            </EndProperty>
          </AssociationSetMapping>
        </EntityContainerMapping>
</Mapping></edmx:Mappings>
  </edmx:Runtime>
  <!-- EF Designer content (DO NOT EDIT MANUALLY BELOW HERE) -->
  <edmx:Designer xmlns="http://schemas.microsoft.com/ado/2008/10/edmx">
    <edmx:Connection>
      <DesignerInfoPropertySet>
        <DesignerProperty Name="MetadataArtifactProcessing" Value="EmbedInOutputAssembly" />
      </DesignerInfoPropertySet>
    </edmx:Connection>
    <edmx:Options>
      <DesignerInfoPropertySet>
        <DesignerProperty Name="ValidateOnBuild" Value="true" />
        <DesignerProperty Name="EnablePluralization" Value="True" />
        <DesignerProperty Name="IncludeForeignKeysInModel" Value="False" />
      </DesignerInfoPropertySet>
    </edmx:Options>
    <!-- Diagram content (shape and connector positions) -->
    <edmx:Diagrams>
      <Diagram Name="Model1" >
        <EntityTypeShape EntityType="Model1.ProcessName" Width="1.5" PointX="0.75" PointY="0.75" Height="1.2636116536458317" />
        <EntityTypeShape EntityType="Model1.Usage" Width="1.5" PointX="3" PointY="0.75" Height="1.7566536458333339" />
        <AssociationConnector Association="Model1.ProcessNameUsage">
          <ConnectorPoint PointX="2.25" PointY="1.4639794921875002" />
          <ConnectorPoint PointX="3" PointY="1.4639794921875002" />
        </AssociationConnector>
      </Diagram>
    </edmx:Diagrams>
  </edmx:Designer>
</edmx:Edmx>

感谢

Answer 1

如果要公开外键ID并使EF管理关系，可以使用外键关联，但这些仅在EF 4.0中可用

Answer 2

解决了它。因此，为了在从sqlite数据库导入模型后使其工作，我执行了以下操作：

a）删除了导入的“ProcessNameId”列

b）然后在这之后添加了两个实体之间的关联 - 它自动使用“ProcessNameId”作为FK id，这与我在数据库中已经匹配的那个很好（否则我将不得不追逐它）

此后事情正常。

EntityFramework映射 - 这个映射有什么问题？

2 个答案: