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SqlUserDefinedAggregateAttribute Class

Indicates that the type should be registered as a user-defined aggregate. The properties on the attribute reflect the physical attributes used when the type is registered with SQL Server. This class cannot be inherited.


Namespace:  Microsoft.SqlServer.Server
Assembly:  System.Data (in System.Data.dll)

[AttributeUsageAttribute(AttributeTargets.Class|AttributeTargets.Struct, AllowMultiple = false, 
	Inherited = false)]
public sealed class SqlUserDefinedAggregateAttribute : Attribute

The SqlUserDefinedAggregateAttribute type exposes the following members.

Public methodSqlUserDefinedAggregateAttributeA required attribute on a user-defined aggregate, used to indicate that the given type is a user-defined aggregate and the storage format of the user-defined aggregate.

Public propertyFormatThe serialization format as a Format.
Public propertyIsInvariantToDuplicatesIndicates whether the aggregate is invariant to duplicates.
Public propertyIsInvariantToNullsIndicates whether the aggregate is invariant to nulls.
Public propertyIsInvariantToOrderIndicates whether the aggregate is invariant to order.
Public propertyIsNullIfEmptyIndicates whether the aggregate returns null if no values have been accumulated.
Public propertyMaxByteSizeThe maximum size, in bytes, of the aggregate instance.
Public propertyNameThe name of the aggregate.
Public propertyTypeIdWhen implemented in a derived class, gets a unique identifier for this Attribute. (Inherited from Attribute.)

Public methodEqualsInfrastructure. Returns a value that indicates whether this instance is equal to a specified object. (Inherited from Attribute.)
Protected methodFinalizeAllows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
Public methodGetHashCodeReturns the hash code for this instance. (Inherited from Attribute.)
Public methodGetTypeGets the Type of the current instance. (Inherited from Object.)
Public methodIsDefaultAttributeWhen overridden in a derived class, indicates whether the value of this instance is the default value for the derived class. (Inherited from Attribute.)
Public methodMatchWhen overridden in a derived class, returns a value that indicates whether this instance equals a specified object. (Inherited from Attribute.)
Protected methodMemberwiseCloneCreates a shallow copy of the current Object. (Inherited from Object.)
Public methodToStringReturns a string that represents the current object. (Inherited from Object.)

Public fieldStatic memberMaxByteSizeValueThe maximum size, in bytes, required to store the state of this aggregate instance during computation.

Explicit interface implemetationPrivate method_Attribute.GetIDsOfNamesMaps a set of names to a corresponding set of dispatch identifiers. (Inherited from Attribute.)
Explicit interface implemetationPrivate method_Attribute.GetTypeInfoRetrieves the type information for an object, which can be used to get the type information for an interface. (Inherited from Attribute.)
Explicit interface implemetationPrivate method_Attribute.GetTypeInfoCountRetrieves the number of type information interfaces that an object provides (either 0 or 1). (Inherited from Attribute.)
Explicit interface implemetationPrivate method_Attribute.InvokeProvides access to properties and methods exposed by an object. (Inherited from Attribute.)

SQL Server creates a user-defined aggregate that is bound to the class definition that has the SqlUserDefinedAggregateAttribute custom attribute. Every user-defined aggregate must be annotated with this attribute.

See "CLR User-Defined Aggregates" in SQL Server 2005 Books Online for more information on user-defined aggregates and examples.

The following example shows the SqlUserDefinedAggregateAttribute attribute for a user-defined aggregate. The aggregate uses custom serialization, has a maximum size of 8000 bytes when serialized, and is invariant to nulls, duplicates, and order.

using System;
using System.IO;
using System.Data.Sql;
using System.Data.SqlTypes;
using System.Text;
using Microsoft.SqlServer.Server;

   IsInvariantToNulls = true,			
   IsInvariantToDuplicates = false,		
   IsInvariantToOrder = false,			
   MaxByteSize = 8000)				
public class Concatenate : Microsoft.SqlServer.Server.IBinarySerialize

.NET Framework

Supported in: 4, 3.5, 3.0, 2.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.