SqlFunctionAttribute Class


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Used to mark a method definition of a user-defined aggregate as a function in SQL Server. The properties on the attribute reflect the physical characteristics used when the type is registered with SQL Server.

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


[AttributeUsageAttribute(AttributeTargets.Method, AllowMultiple = false, 
	Inherited = false)]
public class SqlFunctionAttribute : Attribute


An optional attribute on a user-defined aggregate, used to indicate that the method should be registered in SQL Server as a function. Also used to set the DataAccess, FillRowMethodName, IsDeterministic, IsPrecise, Name, SystemDataAccess, and TableDefinition properties of the function attribute.


Indicates whether the function involves access to user data stored in the local instance of SQL Server.


The name of a method in the same class as the table-valued function (TVF) that is used by the TVF contract.


Indicates whether the user-defined function is deterministic.


Indicates whether the function involves imprecise computations, such as floating point operations.


The name under which the function should be registered in SQL Server.


Indicates whether the function requires access to data stored in the system catalogs or virtual system tables of SQL Server.


A string that represents the table definition of the results, if the method is used as a table-valued function (TVF).


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.)


Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.(Inherited from Object.)


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.)


Creates a shallow copy of the current Object.(Inherited from Object.)


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

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.)

The following example shows an aggregate function that returns a list of files in the specified directory path.

[SqlFunctionAttribute(FillRowMethodName = "FillFileRow")]
public static IEnumerable GetFileDetails(string directoryPath)
      DirectoryInfo di = new DirectoryInfo(directoryPath);
      return di.GetFiles();
   catch (DirectoryNotFoundException dnf)
      return new string[1] { dnf.ToString() };


.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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