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Génération de code dans LINQ to SQL

  • Article

Vous pouvez générer de code pour représenter une base de données à l’aide de Concepteur Objet Relationnel ou de l’outil de ligne de commande SQLMetal. Dans l'un et l'autre cas, la génération du code de bout en bout s'effectue en trois étapes :

  1. L’extracteur DBML extrait des informations de schéma de la base de données et réassemble ces informations en un fichier DBML au format XML.

  2. Le fichier DBML est analysé par le validateur DBML qui recherche les erreurs éventuelles.

  3. Si aucune erreur de validation n’apparaît, le fichier est passé au Générateur de code.

Pour plus d’informations, consultez SqlMetal.exe (outil de génération de code). Les développeurs qui utilisent Visual Studio peuvent également utiliser le Concepteur Objet Relationnel pour générer du code. Consultez LINQ to SQL Tools dans Visual Studio.

Extracteur DBML

L’extracteur DBML est un composant LINQ to SQL qui accepte les métadonnées de base de données en entrée et produit un fichier DBML en sortie.

Générateur de code

Le Générateur de code est un composant LINQ to SQL qui traduit les fichiers DBML en fichiers de mappage Visual Basic, C# ou XML.

Fichier de définition de schéma XML

Le fichier DBML doit être valide par rapport à la définition de schéma suivante en tant que fichier XSD.

Distinguez ce fichier de définition de schéma du fichier de définition de schéma utilisé pour valider un fichier de mappage externe. Pour plus d’informations, consultez Mappage externe).

Notes

Les utilisateurs Visual Studio trouveront également ce fichier XSD dans la boîte de dialogue Schémas XML sous la forme "DbmlSchema.xsd". Pour utiliser correctement le fichier XSD pour valider un fichier DBML, consultez Guide pratique pour valider des fichiers de mappage externes et DBML.

<?xml version="1.0" encoding="utf-16"?>  
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" targetNamespace="http://schemas.microsoft.com/linqtosql/dbml/2007" xmlns="http://schemas.microsoft.com/linqtosql/dbml/2007"  
elementFormDefault="qualified" >  
  <xs:element name="Database" type="Database" />  
  <xs:complexType name="Database">  
    <xs:sequence>  
      <xs:element name="Connection" type="Connection" minOccurs="0" maxOccurs="1" />  
      <xs:element name="Table" type="Table" minOccurs="0" maxOccurs="unbounded" />  
      <xs:element name="Function" type="Function" minOccurs="0" maxOccurs="unbounded" />  
    </xs:sequence>  
    <xs:attribute name="Name" type="xs:string" use="optional" />  
    <xs:attribute name="EntityNamespace" type="xs:string" use="optional" />  
    <xs:attribute name="ContextNamespace" type="xs:string" use="optional" />  
    <xs:attribute name="Class" type="xs:string" use="optional" />  
    <xs:attribute name="AccessModifier" type="AccessModifier" use="optional" />  
    <xs:attribute name="Modifier" type="ClassModifier" use="optional" />  
    <xs:attribute name="BaseType" type="xs:string" use="optional" />  
    <xs:attribute name="Provider" type="xs:string" use="optional" />  
    <xs:attribute name="ExternalMapping" type="xs:boolean" use="optional" />  
    <xs:attribute name="Serialization" type="SerializationMode" use="optional" />  
    <xs:attribute name="EntityBase" type="xs:string" use="optional" />  
  </xs:complexType>  
  <xs:complexType name="Table">  
    <xs:all>  
      <xs:element name="Type" type="Type" minOccurs="1" maxOccurs="1" />  
      <xs:element name="InsertFunction" type="TableFunction" minOccurs="0" maxOccurs="1" />  
      <xs:element name="UpdateFunction" type="TableFunction" minOccurs="0" maxOccurs="1" />  
      <xs:element name="DeleteFunction" type="TableFunction" minOccurs="0" maxOccurs="1" />  
    </xs:all>  
    <xs:attribute name="Name" type="xs:string" use="required" />  
    <xs:attribute name="Member" type="xs:string" use="optional" />  
    <xs:attribute name="AccessModifier" type="AccessModifier" use="optional" />  
    <xs:attribute name="Modifier" type="MemberModifier" use="optional" />  
  </xs:complexType>  
  <xs:complexType name="Type">  
    <xs:sequence>  
      <xs:choice minOccurs="0" maxOccurs="unbounded">  
        <xs:element name="Column" type="Column" minOccurs="0" maxOccurs="unbounded" />  
        <xs:element name="Association" type="Association" minOccurs="0" maxOccurs="unbounded" />  
      </xs:choice>  
      <xs:element name="Type" type="Type" minOccurs="0" maxOccurs="unbounded" />  
    </xs:sequence>  
    <xs:attribute name="IdRef" type="xs:IDREF" use="optional" />  
    <xs:attribute name="Id" type="xs:ID" use="optional" />  
    <xs:attribute name="Name" type="xs:string" use="optional" />  
    <xs:attribute name="InheritanceCode" type="xs:string" use="optional" />  
    <xs:attribute name="IsInheritanceDefault" type="xs:boolean" use="optional" />  
    <xs:attribute name="AccessModifier" type="AccessModifier" use="optional" />  
    <xs:attribute name="Modifier" type="ClassModifier" use="optional" />  
  </xs:complexType>  
  <xs:complexType name="Column">  
    <xs:attribute name="Name" type="xs:string" use="optional" />  
    <xs:attribute name="Member" type="xs:string" use="optional" />  
    <xs:attribute name="Storage" type="xs:string" use="optional" />  
    <xs:attribute name="AccessModifier" type="AccessModifier" use="optional" />  
    <xs:attribute name="Modifier" type="MemberModifier" use="optional" />  
    <xs:attribute name="Type" type="xs:string" use="required" />  
    <xs:attribute name="DbType" type="xs:string" use="optional" />  
    <xs:attribute name="IsReadOnly" type="xs:boolean" use="optional" />  
    <xs:attribute name="IsPrimaryKey" type="xs:boolean" use="optional" />  
    <xs:attribute name="IsDbGenerated" type="xs:boolean" use="optional" />  
    <xs:attribute name="CanBeNull" type="xs:boolean" use="optional" />  
    <xs:attribute name="UpdateCheck" type="UpdateCheck" use="optional" />  
    <xs:attribute name="IsDiscriminator" type="xs:boolean" use="optional" />  
    <xs:attribute name="Expression" type="xs:string" use="optional" />  
    <xs:attribute name="IsVersion" type="xs:boolean" use="optional" />  
    <xs:attribute name="IsDelayLoaded" type="xs:boolean" use="optional" />  
    <xs:attribute name="AutoSync" type="AutoSync" use="optional" />  
  </xs:complexType>  
  <xs:complexType name="Association">  
    <xs:attribute name="Name" type="xs:string" use="required" />  
    <xs:attribute name="Member" type="xs:string" use="required" />  
    <xs:attribute name="Storage" type="xs:string" use="optional" />  
    <xs:attribute name="AccessModifier" type="AccessModifier" use="optional" />  
    <xs:attribute name="Modifier" type="MemberModifier" use="optional" />  
    <xs:attribute name="Type" type="xs:string" use="required" />  
    <xs:attribute name="ThisKey" type="xs:string" use="optional" />  
    <xs:attribute name="OtherKey" type="xs:string" use="optional" />  
    <xs:attribute name="IsForeignKey" type="xs:boolean" use="optional" />  
    <xs:attribute name="Cardinality" type="Cardinality" use="optional" />  
    <xs:attribute name="DeleteRule" type="xs:string" use="optional" />  
    <xs:attribute name="DeleteOnNull" type="xs:boolean" use="optional" />  
  </xs:complexType>  
  <xs:complexType name="Function">  
    <xs:sequence>  
      <xs:element name="Parameter" type="Parameter" minOccurs="0" maxOccurs="unbounded" />  
      <xs:choice>  
        <xs:element name="ElementType" type="Type" minOccurs="0" maxOccurs="unbounded" />  
        <xs:element name="Return" type="Return" minOccurs="0" maxOccurs="1" />  
      </xs:choice>  
    </xs:sequence>  
    <xs:attribute name="Name" type="xs:string" use="required" />  
    <xs:attribute name="Id" type="xs:ID" use="optional" />  
    <xs:attribute name="Method" type="xs:string" use="optional" />  
    <xs:attribute name="AccessModifier" type="AccessModifier" use="optional" />  
    <xs:attribute name="Modifier" type="MemberModifier" use="optional" />  
    <xs:attribute name="HasMultipleResults" type="xs:boolean" use="optional" />  
    <xs:attribute name="IsComposable" type="xs:boolean" use="optional" />  
  </xs:complexType>  
  <xs:complexType name="TableFunction">  
    <xs:sequence>  
      <xs:element name="Argument" type="TableFunctionParameter" minOccurs="0" maxOccurs="unbounded" />  
      <xs:element name="Return" type="TableFunctionReturn" minOccurs="0" maxOccurs="1" />  
    </xs:sequence>  
    <xs:attribute name="FunctionId" type="xs:IDREF" use="required" />  
    <xs:attribute name="AccessModifier" type="AccessModifier" use="optional" />  
  </xs:complexType>  
  <xs:complexType name="Parameter">  
    <xs:attribute name="Name" type="xs:string" use="required" />  
    <xs:attribute name="Parameter" type="xs:string" use="optional" />  
    <xs:attribute name="Type" type="xs:string" use="required" />  
    <xs:attribute name="DbType" type="xs:string" use="optional" />  
    <xs:attribute name="Direction" type="ParameterDirection" use="optional" />  
  </xs:complexType>  
  <xs:complexType name="Return">  
    <xs:attribute name="Type" type="xs:string" use="required" />  
    <xs:attribute name="DbType" type="xs:string" use="optional" />  
  </xs:complexType>  
  <xs:complexType name="TableFunctionParameter">  
    <xs:attribute name="Parameter" type="xs:string" use="required" />  
    <xs:attribute name="Member" type="xs:string" use="required" />  
    <xs:attribute name="Version" type="Version" use="optional" />  
  </xs:complexType>  
  <xs:complexType name="TableFunctionReturn">  
    <xs:attribute name="Member" type="xs:string" use="required" />  
  </xs:complexType>  
  <xs:complexType name="Connection">  
    <xs:attribute name="Provider" type="xs:string" use="required" />  
    <xs:attribute name="Mode" type="ConnectionMode" use="optional" />  
    <xs:attribute name="ConnectionString" type="xs:string" use="optional" />  
    <xs:attribute name="SettingsObjectName" type="xs:string" use="optional" />  
    <xs:attribute name="SettingsPropertyName" type="xs:string" use="optional" />  
  </xs:complexType>  
  <xs:simpleType name="ConnectionMode">  
    <xs:restriction base="xs:string">  
      <xs:enumeration value="ConnectionString" />  
      <xs:enumeration value="AppSettings" />  
      <xs:enumeration value="WebSettings" />  
    </xs:restriction>  
  </xs:simpleType>  
  <xs:simpleType name="AccessModifier">  
    <xs:restriction base="xs:string">  
      <xs:enumeration value="Public" />  
      <xs:enumeration value="Internal" />  
      <xs:enumeration value="Protected" />  
      <xs:enumeration value="ProtectedInternal" />  
      <xs:enumeration value="Private" />  
    </xs:restriction>  
  </xs:simpleType>  
  <xs:simpleType name="UpdateCheck">  
    <xs:restriction base="xs:string">  
      <xs:enumeration value="Always" />  
      <xs:enumeration value="Never" />  
      <xs:enumeration value="WhenChanged" />  
    </xs:restriction>  
  </xs:simpleType>  
  <xs:simpleType name="SerializationMode">  
    <xs:restriction base="xs:string">  
      <xs:enumeration value="None" />  
      <xs:enumeration value="Unidirectional" />  
    </xs:restriction>  
  </xs:simpleType>  
  <xs:simpleType name="ParameterDirection">  
    <xs:restriction base="xs:string">  
      <xs:enumeration value="In" />  
      <xs:enumeration value="Out" />  
      <xs:enumeration value="InOut" />  
    </xs:restriction>  
  </xs:simpleType>  
  <xs:simpleType name="Version">  
    <xs:restriction base="xs:string">  
      <xs:enumeration value="Current" />  
      <xs:enumeration value="Original" />  
    </xs:restriction>  
  </xs:simpleType>  
  <xs:simpleType name="AutoSync">  
    <xs:restriction base="xs:string">  
      <xs:enumeration value="Never" />  
      <xs:enumeration value="OnInsert" />  
      <xs:enumeration value="OnUpdate" />  
      <xs:enumeration value="Always" />  
      <xs:enumeration value="Default" />  
    </xs:restriction>  
  </xs:simpleType>  
  <xs:simpleType name="ClassModifier">  
    <xs:restriction base="xs:string">  
      <xs:enumeration value="Sealed" />  
      <xs:enumeration value="Abstract" />  
    </xs:restriction>  
  </xs:simpleType>  
  <xs:simpleType name="MemberModifier">  
    <xs:restriction base="xs:string">  
      <xs:enumeration value="Virtual" />  
      <xs:enumeration value="Override" />  
      <xs:enumeration value="New" />  
      <xs:enumeration value="NewVirtual" />  
    </xs:restriction>  
  </xs:simpleType>  
  <xs:simpleType name="Cardinality">  
    <xs:restriction base="xs:string">  
      <xs:enumeration value="One" />  
      <xs:enumeration value="Many" />  
    </xs:restriction>  
  </xs:simpleType>  
</xs:schema>

Exemple de fichier DBML

Le code suivant est un extrait du fichier DBML créé à partir de la base de données d'exemple Northwind. Vous pouvez générer le fichier entier en utilisant SQLMetal avec l’option /xml. Pour plus d’informations, consultez SqlMetal.exe (outil de génération de code).

<?xml version="1.0" encoding="utf-16"?>  
<Database Name="northwnd" Class="Northwnd" xmlns="http://schemas.microsoft.com/dsltools/DLinqML">  
  
  <Table Name="Customers">  
    <Type Name="Customer">  
      <Column Name="CustomerID" Type="System.String" DbType="NChar(5) NOT NULL" IsPrimaryKey="True" CanBeNull="False" />  
      <Column Name="CompanyName" Type="System.String" DbType="NVarChar(40) NOT NULL" CanBeNull="False" />  
      <Column Name="ContactName" Type="System.String" DbType="NVarChar(30)" CanBeNull="True" />  
      <Column Name="ContactTitle" Type="System.String" DbType="NVarChar(30)" CanBeNull="True" />  
      <Column Name="Address" Type="System.String" DbType="NVarChar(60)" CanBeNull="True" />  
      <Column Name="City" Type="System.String" DbType="NVarChar(15)" CanBeNull="True" />  
      <Column Name="Region" Type="System.String" DbType="NVarChar(15)" CanBeNull="True" />  
      <Column Name="PostalCode" Type="System.String" DbType="NVarChar(10)" CanBeNull="True" />  
      <Column Name="Country" Type="System.String" DbType="NVarChar(15)" CanBeNull="True" />  
      <Column Name="Phone" Type="System.String" DbType="NVarChar(24)" CanBeNull="True" />  
      <Column Name="Fax" Type="System.String" DbType="NVarChar(24)" CanBeNull="True" />  
      <Association Name="FK_CustomerCustomerDemo_Customers" Member="CustomerCustomerDemos" ThisKey="CustomerID" OtherKey="CustomerID" OtherTable="CustomerCustomerDemo" DeleteRule="NO ACTION" />  
      <Association Name="FK_Orders_Customers" Member="Orders" ThisKey="CustomerID" OtherKey="CustomerID" OtherTable="Orders" DeleteRule="NO ACTION" />  
    </Type>  
  </Table>  
</Database>

Voir aussi