System.Data.Metadata.Edm 命名空间

System.Data.Metadata.Edm 命名空间包含一组类型和一组类,前者表示 Entity Framework 在模型中普遍使用的概念,后者则有助于应用程序对元数据进行处理。 The System.Data.Metadata.Edm namespace contains a set of types that represent concepts throughout the models used by the Entity Framework and a set of classes that help applications to work with metadata.

AssociationEndMember

表示概念模型中的关联的 EndRepresents the End of an association in the conceptual model.

AssociationSet

表示概念模型中的关联集。Represents an association set in the conceptual model.

AssociationSetEnd

表示概念模型中的关联集的 EndRepresents the End of the association set in a conceptual model.

AssociationType

表示概念模型中的关联。Represents an association in a conceptual model.

CollectionType

表示特定类型的实例的集合。Represents a collection of instances of a specific type. 不能在概念模型中显式定义 CollectionTypeYou cannot explicitly define a CollectionType in a conceptual model.

ComplexType

表示概念模型中的复杂类型。Represents a complex type in a conceptual model.

Documentation

表示与概念模型结构关联的文档。Represents the documentation associated with a conceptual model construct.

EdmError

封装有关概念模型的一般性错误的错误信息。Encapsulates the error information for a generic conceptual model error.

EdmFunction

表示关于函数的信息,从使用实体 SQL 查询语言编写的查询中可以调用这些函数。Represents information about the functions that may be invoked from the queries written by the Entity SQL query language. 这些函数可能是由存储提供程序公开的内置函数,也可能是特定数据库中由用户定义的函数。These may be the built-in functions exposed by the storage provider or user-defined functions in a particular database.

EdmItemCollection

加载有关概念模型的元数据。Loads metadata about the conceptual model. “EdmItemCollection”用于加载概念性架构定义语言 (CSDL) 文件中的元数据。The EdmItemCollection loads metadata from conceptual schema definition language (CSDL) files. 此类派生自 ItemCollection 类。This class is derived from the ItemCollection class.

EdmMember

表示可在任意 StructuralType 中声明的成员。Represents a member that can be declared in any StructuralType.

EdmProperty

表示概念模型中 EntityType 的属性。Represents a property for the EntityType in a conceptual model. EdmProperty 类派生自 EdmMember 类,可提供此 DefaultValue 的类型的 NullableEdmProperty 方面。An EdmProperty class derives from the EdmMember class and provides the DefaultValue and the Nullable facets for the type of this EdmProperty.

EdmSchemaError

封装有关概念模型架构错误的详细信息。Encapsulates the detailed information about a conceptual model schema error.

EdmType

表示概念模型中的所有类型的基类。Represents a base class for all the types in a conceptual model.

EntityContainer

表示概念模型中的实体容器。Represents an entity container in a conceptual model. EntityContainer 是实体集和关联集的逻辑分组。An EntityContainer is a logical grouping of entity sets and association sets.

EntitySet

表示概念模型中的实体集。Represents an entity set in a conceptual model. EntitySetEntityType 包含 EntityType 或其任何子类型的实例。An EntitySet for an EntityType contains instances of the EntityType or any of its subtypes. 可以使用同一个 EntitySet 定义多个 EntityTypeMore than one EntitySet can be defined by using the same EntityType.

EntitySetBase

EntitySetRelationshipSet 的基类。A base class for an EntitySet and a RelationshipSet.

EntityType

表示特定类型的数据,例如概念模型中的客户实体或订单实体。Represents a particular type of data, such as a customer entity or an order entity in a conceptual model.

EntityTypeBase

EntityTypeRelationshipType 的基类型。A base type for EntityType and RelationshipType.

EnumMember

表示枚举成员。Represents an enumeration member.

EnumType

表示枚举类型。Represents an enumeration type.

Facet

提供有关成员的其他信息。Provides additional information about members. 在 ADO.NET 元数据类型层次结构中,Facet 可通过成员的已声明类型提供有关该成员的其他信息。In the ADO.NET metadata type hierarchy, facets provide additional information about members through the declared type for the member.

FacetDescription

指定对方面的说明。Specifies a description of the facet.

FunctionParameter

描述 EdmFunction 的参数。Describes the parameters of an EdmFunction.

GlobalItem

表示所有概念模型类型和实体容器的基项类。Represents the base item class for all the conceptual model types and entity containers.

ItemCollection

ObjectItemCollectionEdmItemCollectionStorageMappingItemCollection 类的基类。A base class for ObjectItemCollection, EdmItemCollection, and StorageMappingItemCollection classes. ItemCollection 类是一个抽象类,可提供用于加载和保存内存中的元数据的核心 API。An ItemCollection class is an abstract class and provides the core API for loading and holding the in-memory metadata. 此类派生自 ReadOnlyMetadataCollection<T> 类。This class is derived from the ReadOnlyMetadataCollection<T> class.

MetadataItem

表示 ADO.NET 元数据类型层次结构中所有元数据的基项类。Represents the base item class for all the metadata in the ADO.NET metadata type hierarchy.

MetadataProperty

表示 ADO.NET 元数据层次结构中的项的元数据属性。Represents a metadata attribute for an item in the ADO.NET metadata hierarchy.

MetadataWorkspace

表示 ADO.NET 元数据运行时服务组件,该组件可为从各种源检索元数据提供支持。Represents the ADO.NET metadata runtime service component that provides support for retrieving metadata from various sources.

NavigationProperty

表示概念模型中从一个实体类型到另一个实体类型的导航。Represents the navigation from one entity type to another entity type in the conceptual model .

ObjectItemCollection

向该对象层表示项的集合的类。Class for representing a collection of items for the object layer. 集合的大部分实际维护的实现由 ItemCollection 完成。Most of the implementation for actual maintenance of the collection is done by ItemCollection.

PrimitiveType

描述 .NET Framework 基元类型、概念模型基元类型和特定于存储提供程序的基元类型。Describes the .NET Framework primitive types, conceptual model primitive types, and storage provider-specific primitive types.

ReadOnlyMetadataCollection<T>

通过提供具有高级查找功能的只读集合表示 ADO.NET 元数据层次结构中的成员集合。Represents a collection of members in the ADO.NET metadata hierarchy by providing a read-only collection with advanced lookup capabilities. 此类派生自 ReadOnlyCollection<T> 类。This class is derived from the ReadOnlyCollection<T> class.

ReferentialConstraint

描述对概念模型中的关系的引用约束。Describes the referential constraints on the relationships in a conceptual model.

RefType

提供实体的地址,供使用该实体的操作使用。Provides the address of an entity for operations that use the entity. 不能在概念模型架构中显式定义 RefTypeYou cannot define a RefType in a conceptual model schema explicitly.

RelationshipEndMember

定义 RelationshipTypeEnd 成员。Defines the End member for the RelationshipType.

RelationshipSet

表示概念模型中的关系集。Represents a relationship set in a conceptual model.

RelationshipType

表示概念模型中的关系的基类。Represents the base class for relationships in a conceptual model.

RowType

描述一个行,例如查询的结果。Describes a row, such as the result of a query. 此类派生自 StructuralType 类。This class is derived from the StructuralType class. 行类型的结构取决于查询中提取的数据库列。The structure of the row type depends on what database columns are projected in the query. RowType概念模型函数中非常有用。The RowType can be useful in conceptual model functions.

SimpleType

一个描述概念模型中的基元类型的基类。A base class that describes primitive types in a conceptual model.

StoreItemCollection

加载有关存储(数据库)模型的元数据。Loads metadata about the storage (database) model. StoreItemCollection 用于加载存储架构定义语言 (SSDL) 文件中的元数据。The StoreItemCollection loads metadata from store schema definition language (SSDL) files. 此类派生自 ItemCollection 类。This class is derived from the ItemCollection class.

StructuralType

概念模型中拥有成员的所有类型的基类型。A base type for all the types in a conceptual model that have members.

TypeUsage

描述一个类型以及该类型的一组方面。Describes a type and a set of facets for that type.

结构

ReadOnlyMetadataCollection<T>.Enumerator

支持对 ReadOnlyMetadataCollection<T> 集合执行简单迭代。Supports a simple iteration over the ReadOnlyMetadataCollection<T> collection.

枚举

BuiltInTypeKind

表示一个枚举,该枚举指定概念模型中所有内置类型的列表。Represents an enumeration that specifies the list of all built-in types in a conceptual model.

CollectionKind

表示一个枚举,该枚举指定应用于概念性架构定义语言 (CSDL) 文件中的属性的集合类型。 该集合类型可以应用于任何类型的属性。You can apply this to the properties of any type.

ConcurrencyMode

指定概念模型中的属性的并发选项。Specifies the concurrency options for the properties in a conceptual model.

DataSpace

指定 Entity Framework 中的模型的默认名称。Specifies the default names for the models in the Entity Framework.

EdmSchemaErrorSeverity

指定错误的严重级别。Specifies the severity level of the error.

OperationAction

指定在删除 RelationshipType 的父 End 时可能进行的操作的列表。Specifies the list of possible actions when the parent End of the RelationshipType is deleted.

ParameterMode

指定参数的方向。Specifies the direction of a parameter.

ParameterTypeSemantics

指定用于解析函数重载的类型语义。 在提供程序清单文件中,每个存储提供程序都必须使用这些枚举标志来定义每个函数。Each store provider must use these enumeration flags in the provider manifest file for every function definition.

PrimitiveTypeKind

指定由 EDM 定义的基元类型。Specifies the primitive types as defined by EDM.

PropertyKind

指定概念模型中项特性的类型。Specifies the kinds of item attributes in the conceptual model.

RelationshipMultiplicity

表示与关系类型的 End 有关的重数信息。Represents the multiplicity information about the End of a relationship type.

StoreGeneratedPattern

表示一个枚举,它指定三个选项,用于指示存储架构定义语言 (SSDL) (.ssdl) 中的列在插入和更新操作期间是否需要值。 ADO.NET 读取该列的值,然后将其存储在内存中的缓存内。ADO.NET reads the value of the column and then stores it in-memory cache.

注解

有关如何使用此命名空间的详细信息,请参阅ADO.NET 元数据For more information about how to use this namespace, see ADO.NET Metadata.