Crear tipos definidos por el usuario
Se aplica a: 
SQL Server
Para crear un tipo definido por el usuario (UDT) capaz de instalarse en SQL Server, primero debe crear una clase en uno de los lenguajes de programación de .NET Framework compatibles, como Visual C# o Visual Basic, que se ajusta a las especificaciones para crear UDT. A continuación, la clase se puede compilar como una biblioteca de vínculos dinámicos (DLL), que se puede cargar en SQL Server. También puede crear e implementar UDT con Visual Studio.
La capacidad de ejecutar código de Common Language Runtime (CLR) se establece en OFF de forma predeterminada en SQL Server. CLR se puede habilitar mediante el procedimiento almacenado del sistema sp_configure , como se muestra en las siguientes instrucciones Transact-SQL:
sp_configure 'clr enabled', 1
Reconfigure
En esta sección
Requisitos de tipos definidos por el usuario
Describe los requisitos para codificar los tipos definidos por el usuario.
Codificar tipos definidos por el usuario
Muestra las técnicas de codificación implicadas en la creación de tipos definidos por el usuario.
Ejemplo
La siguiente lista de código define el UDT de punto, que se describe en detalle en Codificación de tipos definidos por el usuario.
C#
using System;
using System.Data;
using System.Data.SqlTypes;
using Microsoft.SqlServer.Server;
using System.Text;
[Serializable]
[Microsoft.SqlServer.Server.SqlUserDefinedType(Format.Native,
IsByteOrdered=true, ValidationMethodName = "ValidatePoint")]
public struct Point : INullable
{
private bool is_Null;
private Int32 _x;
private Int32 _y;
public bool IsNull
{
get
{
return (is_Null);
}
}
public static Point Null
{
get
{
Point pt = new Point();
pt.is_Null = true;
return pt;
}
}
// Use StringBuilder to provide string representation of UDT.
public override string ToString()
{
// Since InvokeIfReceiverIsNull defaults to 'true'
// this test is unnecessary if Point is only being called
// from SQL.
if (this.IsNull)
return "NULL";
else
{
StringBuilder builder = new StringBuilder();
builder.Append(_x);
builder.Append(",");
builder.Append(_y);
return builder.ToString();
}
}
[SqlMethod(OnNullCall = false)]
public static Point Parse(SqlString s)
{
// With OnNullCall=false, this check is unnecessary if
// Point only called from SQL.
if (s.IsNull)
return Null;
// Parse input string to separate out points.
Point pt = new Point();
string[] xy = s.Value.Split(",".ToCharArray());
pt.X = Int32.Parse(xy[0]);
pt.Y = Int32.Parse(xy[1]);
// Call ValidatePoint to enforce validation
// for string conversions.
if (!pt.ValidatePoint())
throw new ArgumentException("Invalid XY coordinate values.");
return pt;
}
// X and Y coordinates exposed as properties.
public Int32 X
{
get
{
return this._x;
}
// Call ValidatePoint to ensure valid range of Point values.
set
{
Int32 temp = _x;
_x = value;
if (!ValidatePoint())
{
_x = temp;
throw new ArgumentException("Invalid X coordinate value.");
}
}
}
public Int32 Y
{
get
{
return this._y;
}
set
{
Int32 temp = _y;
_y = value;
if (!ValidatePoint())
{
_y = temp;
throw new ArgumentException("Invalid Y coordinate value.");
}
}
}
// Validation method to enforce valid X and Y values.
private bool ValidatePoint()
{
// Allow only zero or positive integers for X and Y coordinates.
if ((_x >= 0) && (_y >= 0))
{
return true;
}
else
{
return false;
}
}
// Distance from 0 to Point method.
[SqlMethod(OnNullCall = false)]
public Double Distance()
{
return DistanceFromXY(0, 0);
}
// Distance from Point to the specified point method.
[SqlMethod(OnNullCall = false)]
public Double DistanceFrom(Point pFrom)
{
return DistanceFromXY(pFrom.X, pFrom.Y);
}
// Distance from Point to the specified x and y values method.
[SqlMethod(OnNullCall = false)]
public Double DistanceFromXY(Int32 iX, Int32 iY)
{
return Math.Sqrt(Math.Pow(iX - _x, 2.0) + Math.Pow(iY - _y, 2.0));
}
}
Visual Basic
Option Explicit On
Option Strict On
Imports System
Imports System.Data.SqlTypes
Imports Microsoft.SqlServer.Server
Imports System.Text
<Serializable(), SqlUserDefinedTypeAttribute(Format.Native, _
IsByteOrdered:=True, _
ValidationMethodName:="ValidatePoint")> _
Public Structure Point
Implements INullable
Private is_Null As Boolean
Private _x As Int32
Private _y As Int32
Public ReadOnly Property IsNull() As Boolean _
Implements INullable.IsNull
Get
Return (is_Null)
End Get
End Property
Public Shared ReadOnly Property Null() As Point
Get
Dim pt As New Point
pt.is_Null = True
Return (pt)
End Get
End Property
' Use StringBuilder to provide string representation of UDT.
Public Overrides Function ToString() As String
' Since InvokeIfReceiverIsNull defaults to 'true'
' this test is unnecessary if Point is only being called
' from SQL.
If Me.IsNull Then
Return "NULL"
Else
Dim builder As StringBuilder = New StringBuilder
builder.Append(_x)
builder.Append(",")
builder.Append(_y)
Return builder.ToString
End If
End Function
<SqlMethod(OnNullCall:=False)> _
Public Shared Function Parse(ByVal s As SqlString) As Point
' With OnNullCall=False, this check is unnecessary if
' Point only being called from SQL.
If s.IsNull Then
Return Null
End If
' Parse input string here to separate out points.
Dim pt As New Point()
Dim xy() As String = s.Value.Split(",".ToCharArray())
pt.X = Int32.Parse(xy(0))
pt.Y = Int32.Parse(xy(1))
' Call ValidatePoint to enforce validation
' for string conversions.
If Not pt.ValidatePoint() Then
Throw New ArgumentException("Invalid XY coordinate values.")
End If
Return pt
End Function
' X and Y coordinates are exposed as properties.
Public Property X() As Int32
Get
Return (Me._x)
End Get
Set(ByVal Value As Int32)
Dim temp As Int32 = _x
_x = Value
If Not ValidatePoint() Then
_x = temp
Throw New ArgumentException("Invalid X coordinate value.")
End If
End Set
End Property
Public Property Y() As Int32
Get
Return (Me._y)
End Get
Set(ByVal Value As Int32)
Dim temp As Int32 = _y
_y = Value
If Not ValidatePoint() Then
_y = temp
Throw New ArgumentException("Invalid Y coordinate value.")
End If
End Set
End Property
' Validation method to enforce valid X and Y values.
Private Function ValidatePoint() As Boolean
' Allow only zero or positive integers for X and Y coordinates.
If (_x >= 0) And (_y >= 0) Then
Return True
Else
Return False
End If
End Function
' Distance from 0 to Point method.
<SqlMethod(OnNullCall:=False)> _
Public Function Distance() As Double
Return DistanceFromXY(0, 0)
End Function
' Distance from Point to the specified point method.
<SqlMethod(OnNullCall:=False)> _
Public Function DistanceFrom(ByVal pFrom As Point) As Double
Return DistanceFromXY(pFrom.X, pFrom.Y)
End Function
' Distance from Point to the specified x and y values method.
<SqlMethod(OnNullCall:=False)> _
Public Function DistanceFromXY(ByVal ix As Int32, ByVal iy As Int32) _
As Double
Return Math.Sqrt(Math.Pow(ix - _x, 2.0) + Math.Pow(iy - _y, 2.0))
End Function
End Structure