ForEachLoop.PrecedenceConstraints Propiedad

Definición

Espacio de nombres:

Microsoft.SqlServer.Dts.Runtime

Ensamblado:

Microsoft.SqlServer.ManagedDTS.dll

Devuelve una colección PrecedenceConstraints que contiene todas las restricciones de precedencia asociadas al bucle ForEachLoop.

public:
 property Microsoft::SqlServer::Dts::Runtime::PrecedenceConstraints ^ PrecedenceConstraints { Microsoft::SqlServer::Dts::Runtime::PrecedenceConstraints ^ get(); };

public Microsoft.SqlServer.Dts.Runtime.PrecedenceConstraints PrecedenceConstraints { get; }

member this.PrecedenceConstraints : Microsoft.SqlServer.Dts.Runtime.PrecedenceConstraints

Public ReadOnly Property PrecedenceConstraints As PrecedenceConstraints

Valor de propiedad

PrecedenceConstraints

Colección PrecedenceConstraints.

Implementaciones

PrecedenceConstraints

Ejemplos

En el ejemplo de código siguiente se crea y ForEachLoop se establecen algunas propiedades mediante la Properties colección . Se agregan dos tareas a la Executables colección y se coloca una restricción de precedencia entre ellas.

// Create the package.  
Package package = new Package();  
// Add variables.  
package.Variables.Add("Id", false, "User", 0);  

// Create ForEachLoop task  
Executables executables = package.Executables;  
ForEachLoop forEachLoop = executables.Add("STOCK:FOREACHLOOP") as ForEachLoop;  

// The ForEachLoop is a container. Add some task executables and  
// create a precedence constraint. The tasks can run when  
// certain conditions in the loop are met.  
TaskHost thLoopMail = (TaskHost)forEachLoop.Executables.Add("STOCK:SendMailTask");  
TaskHost thLoopInsert = (TaskHost)forEachLoop.Executables.Add("STOCK:BulkInsertTask");  
Executables loopExecs = forEachLoop.Executables;  
Console.WriteLine("Number of Executables in ForLoop: {0}", loopExecs.Count);  

// Like other containers, precedence constraints can be set on the  
// contained tasks.  
PrecedenceConstraint pc = forEachLoop.PrecedenceConstraints.Add((Executable)thLoopMail, thLoopInsert);  
PrecedenceConstraints pcs = forEachLoop.PrecedenceConstraints;  
Console.WriteLine("Number of precedence constraints: {0}", pcs.Count);  

' Create the package.  
Dim package As Package =  New Package()   
' Add variables.  
package.Variables.Add("Id", False, "User", 0)  

' Create ForEachLoop task  
Dim executables As Executables =  package.Executables   
Dim forEachLoop As ForEachLoop =  executables.Add("STOCK:FOREACHLOOP") as ForEachLoop   

' The ForEachLoop is a container. Add some task executables and  
' create a precedence constraint. The tasks can run when  
' certain conditions in the loop are met.  
Dim thLoopMail As TaskHost = CType(forEachLoop.Executables.Add("STOCK:SendMailTask"), TaskHost)  
Dim thLoopInsert As TaskHost = CType(forEachLoop.Executables.Add("STOCK:BulkInsertTask"), TaskHost)  
Dim loopExecs As Executables =  forEachLoop.Executables   
Console.WriteLine("Number of Executables in ForLoop: {0}", loopExecs.Count)  

' Like other containers, precedence constraints can be set on the  
' contained tasks.  
Dim pc As PrecedenceConstraint =  forEachLoop.PrecedenceConstraints.Add(CType(thLoopMail,thLoopInsert, Executable))   
Dim pcs As PrecedenceConstraints =  forEachLoop.PrecedenceConstraints   
Console.WriteLine("Number of precedence constraints: {0}", pcs.Count)  

Salida del ejemplo:

Número de ejecutables en ForLoop: 2

Número de restricciones de precedencia: 1

Comentarios

El orden de ejecución de los objetos de la colección viene determinado por el PrecedenceConstraints agregado al contenedor. PrecedenceConstraints permitir la bifurcación de ejecución en función del éxito, error o finalización de un archivo ejecutable en la colección.