InheritanceMappingAttribute Class
Microsoft Silverlight will reach end of support after October 2021. Learn more.
Maps an inheritance hierarchy in a LINQ to SQL application.
Inheritance Hierarchy
System.Object
System.Attribute
System.Data.Linq.Mapping.InheritanceMappingAttribute
Namespace: System.Data.Linq.Mapping
Assembly: System.Data.Linq (in System.Data.Linq.dll)
Syntax
'Declaration
<AttributeUsageAttribute(AttributeTargets.Class, AllowMultiple := True, Inherited := False)> _
Public NotInheritable Class InheritanceMappingAttribute _
Inherits Attribute
[AttributeUsageAttribute(AttributeTargets.Class, AllowMultiple = true, Inherited = false)]
public sealed class InheritanceMappingAttribute : Attribute
The InheritanceMappingAttribute type exposes the following members.
Constructors
| Name | Description | |
|---|---|---|
.gif "Public method") .gif "Supported by Silverlight for Windows Phone") |
InheritanceMappingAttribute | Initializes a new instance of the InheritanceMappingAttribute class. |
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Properties
| Name | Description | |
|---|---|---|
.gif "Public property") |
Code | Gets or sets the discriminator code value in a mapped inheritance hierarchy. |
|
IsDefault | Gets or sets whether an object of this type in instantiated when the discriminator value does not match a specified value. |
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Type | Gets or sets the type of the class in the hierarchy. |
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Methods
| Name | Description | |
|---|---|---|
|
Equals | Infrastructure. Returns a value that indicates whether this instance is equal to a specified object. (Inherited from Attribute.) |
.gif "Protected method") |
Finalize | Allows an object to try to free resources and perform other cleanup operations before the Object is reclaimed by garbage collection. (Inherited from Object.) |
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GetHashCode | Returns the hash code for this instance. (Inherited from Attribute.) |
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GetType | Gets the Type of the current instance. (Inherited from Object.) |
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Match | When overridden in a derived class, returns a value that indicates whether this instance equals a specified object. (Inherited from Attribute.) |
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MemberwiseClone | Creates a shallow copy of the current Object. (Inherited from Object.) |
|
ToString | Returns a string that represents the current object. (Inherited from Object.) |
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Remarks
One InheritanceMappingAttribute is specified per mapped class.
Note the following when you map inheritance hierarchies:
All classes in a hierarchy must be mapped to a single table.
The table for an inheritance hierarchy must be declared on the mapped type that is at the top of the hierarchy. You cannot specify the table or mapping attributes in a class that is derived from the top class.
You can use an interface in a hierarchy, but LINQ does not map it.
You can skip a class in the hierarchy when you map classes, but you can query against mapped classes only.
For correct materialization, discriminator code values must be unique and match the values in the database. A row with a discriminator code value that does not exactly match (even by casing) instantiates the class by using IsDefault set to true.
| Topic | Location |
|---|---|
| Inheritance Support (LINQ to SQL) | LINQ to SQL |
| Attribute-Based Mapping (LINQ to SQL) | LINQ to SQL |
| How to: Map Inheritance Hierarchies (LINQ to SQL) | LINQ to SQL |
| Inheritance Support (LINQ to SQL) | LINQ to SQL |
| Attribute-Based Mapping (LINQ to SQL) | LINQ to SQL |
| How to: Map Inheritance Hierarchies (LINQ to SQL) | LINQ to SQL |
Version Information
Silverlight for Windows Phone
Supported in: Windows Phone OS 7.1
Platforms
For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.
Thread Safety
Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.