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 Or AttributeTargets.Struct,
	AllowMultiple := False, Inherited := False)>
Public NotInheritable Class SqlUserDefinedAggregateAttribute
	Inherits Attribute


A 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.


The serialization format as a Format.


Indicates whether the aggregate is invariant to duplicates.


Indicates whether the aggregate is invariant to nulls.


Indicates whether the aggregate is invariant to order.


Indicates whether the aggregate returns null if no values have been accumulated.


The maximum size, in bytes, of the aggregate instance.


The name of the aggregate.


When implemented in a derived class, gets a unique identifier for this Attribute.(Inherited from Attribute.)


This API supports the product infrastructure and is not intended to be used directly from your code. Returns a value that indicates whether this instance is equal to a specified object.(Inherited from Attribute.)


Returns the hash code for this instance.(Inherited from Attribute.)


Gets the Type of the current instance.(Inherited from Object.)


When overridden in a derived class, indicates whether the value of this instance is the default value for the derived class.(Inherited from Attribute.)


When overridden in a derived class, returns a value that indicates whether this instance equals a specified object.(Inherited from Attribute.)


Returns a string that represents the current object.(Inherited from Object.)


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

System_CAPS_pubinterfaceSystem_CAPS_privmethod_Attribute.GetIDsOfNames(Guid, IntPtr, UInt32, UInt32, IntPtr)

Maps a set of names to a corresponding set of dispatch identifiers.(Inherited from Attribute.)

System_CAPS_pubinterfaceSystem_CAPS_privmethod_Attribute.GetTypeInfo(UInt32, UInt32, IntPtr)

Retrieves the type information for an object, which can be used to get the type information for an interface.(Inherited from Attribute.)


Retrieves the number of type information interfaces that an object provides (either 0 or 1).(Inherited from Attribute.)

System_CAPS_pubinterfaceSystem_CAPS_privmethod_Attribute.Invoke(UInt32, Guid, UInt32, Int16, IntPtr, IntPtr, IntPtr, IntPtr)

Provides 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.

Imports System
Imports System.Data
Imports System.IO
Imports Microsoft.SqlServer.Server

<Serializable(), SqlUserDefinedAggregate(Microsoft.SqlServer.Server.Format.UserDefined, _ 
                                         IsInvariantToNulls:=True, _ 
                                         IsInvariantToDuplicates:=False, _
                                         IsInvariantToOrder:=False, _
                                         MaxByteSize:=8000)> _
Public Class Concatenate
    Implements Microsoft.SqlServer.Server.IBinarySerialize

.NET Framework
Available since 2.0

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

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