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)
The SqlUserDefinedAggregateAttribute type exposes the following members.
| Name | Description | |
|---|---|---|
 | SqlUserDefinedAggregateAttribute | 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. |
| Name | Description | |
|---|---|---|
| Format | The serialization format as a Format. |
| IsInvariantToDuplicates | Indicates whether the aggregate is invariant to duplicates. |
| IsInvariantToNulls | Indicates whether the aggregate is invariant to nulls. |
| IsInvariantToOrder | Indicates whether the aggregate is invariant to order. |
| IsNullIfEmpty | Indicates whether the aggregate returns null if no values have been accumulated. |
| MaxByteSize | The maximum size, in bytes, of the aggregate instance. |
| Name | The name of the aggregate. |
| TypeId | When implemented in a derived class, gets a unique identifier for this Attribute. (Inherited from Attribute.) |
| Name | Description | |
|---|---|---|
| Equals | Infrastructure. Returns a value that indicates whether this instance is equal to a specified object. (Inherited from Attribute.) |
| GetHashCode | Returns the hash code for this instance. (Inherited from Attribute.) |
| GetType | Gets the Type of the current instance. (Inherited from Object.) |
| IsDefaultAttribute | When overridden in a derived class, indicates whether the value of this instance is the default value for the derived class. (Inherited from Attribute.) |
| Match | When overridden in a derived class, returns a value that indicates whether this instance equals a specified object. (Inherited from Attribute.) |
| ToString | Returns a string that represents the current object. (Inherited from Object.) |
| Name | Description | |
|---|---|---|
| MaxByteSizeValue | The maximum size, in bytes, required to store the state of this aggregate instance during computation. |
| Name | Description | |
|---|---|---|
| _Attribute.GetIDsOfNames | Maps a set of names to a corresponding set of dispatch identifiers. (Inherited from Attribute.) |
| _Attribute.GetTypeInfo | Retrieves the type information for an object, which can be used to get the type information for an interface. (Inherited from Attribute.) |
| _Attribute.GetTypeInfoCount | Retrieves the number of type information interfaces that an object provides (either 0 or 1). (Inherited from Attribute.) |
| _Attribute.Invoke | 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.
using System; using System.IO; using System.Data.Sql; using System.Data.SqlTypes; using System.Text; using Microsoft.SqlServer.Server; [Serializable] [Microsoft.SqlServer.Server.SqlUserDefinedAggregate( Microsoft.SqlServer.Server.Format.UserDefined, IsInvariantToNulls = true, IsInvariantToDuplicates = false, IsInvariantToOrder = false, MaxByteSize = 8000) ] public class Concatenate : Microsoft.SqlServer.Server.IBinarySerialize {
Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)
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