Sequence.PrecedenceConstraints Eigenschaft

Definition

Gibt eine Auflistung von PrecedenceConstraint-Objekten zurück, die die Rangfolgeneinschränkungen beschreiben, die Container und Tasks auf Containerebene mit einer geordneten Ablaufsteuerung verknüpfen.

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

Eigenschaftswert

Eine PrecedenceConstraints-Auflistung.

Implementiert

Beispiele

Im folgenden Codebeispiel wird ein Sequence Objekt erstellt und drei Vorgänge erstellt, wobei Vorrangeinschränkungen zwischen ihnen platziert werden. Mithilfe der PrecedenceConstraints Auflistung werden die Einschränkungen in der Sequence, Druckinformationen zu jeder Einschränkung durchläuft.

using System;  
using System.Collections.Generic;  
using System.Text;    
using Microsoft.SqlServer.Dts.Runtime;  
using Microsoft.SqlServer.Dts.Tasks. FileSystemTask;  

namespace Sequence_API  
{  
    class Program  
    {  
        static void Main(string[] args)  
        {  
            Package package = new Package();  
            Sequence seq = (Sequence)package.Executables.Add("STOCK:SEQUENCE");  

            // Add a File System task.  
            Executable eFileTask1 = seq.Executables.Add("STOCK:FileSystemTask");  
            TaskHost thFileTask1 = eFileTask1 as TaskHost;  

            // Add a second File System task.  
            Executable eFileTask2 = seq.Executables.Add("STOCK:FileSystemTask");  
            TaskHost thFileTask2 = eFileTask2 as TaskHost;  

            // Add a Bulk Insert task.  
            Executable eBulkInsert = seq.Executables.Add("STOCK:BulkInsertTask");  
            TaskHost thBulkInsert = eBulkInsert as TaskHost;  

            // Add a precedence contraint between eFileTask1 and eFileTask2.  
            // Set the constraint to be that eFileTask2 cannot run   
            // until eFileTask1 completes.  
            PrecedenceConstraint pcFileTasks = seq.PrecedenceConstraints.Add(eFileTask1, eFileTask2);  

            // Add another precedence contraint. Add it between eFileTask2 and BulkInsert.  
            // Again, set the constraint to be that BulkInsert cannot run   
            // until eFileTask2 completes.  
            PrecedenceConstraint pcFiletoBulk = seq.PrecedenceConstraints.Add(eFileTask2, eBulkInsert);  
            // Obtain the precedence constraint collection, and display properties.  
            // Some properties are read/write and have not been set.  
            PrecedenceConstraints seqPCs = seq.PrecedenceConstraints;  
            int numPCs = seqPCs.Count;  
            Console.WriteLine("Number of precedence constraints in Sequence: {0}", numPCs);  
            Console.WriteLine("----------------------------------------");  

            foreach (PrecedenceConstraint pc in seqPCs)  
            {  
                Console.WriteLine("Constrained container  {0}", pc.ConstrainedExecutable);  
                Console.WriteLine("Description            {0}", pc.Description);  
                Console.WriteLine("Evaluation operation   {0}", pc.EvalOp);  
                Console.WriteLine("Evaluates true         {0}", pc.EvaluatesTrue);  
                Console.WriteLine("ID                     {0}", pc.ID);  
                Console.WriteLine("LogicalAnd             {0}", pc.LogicalAnd);  
                Console.WriteLine("Name                   {0}", pc.Name);  
                Console.WriteLine("Precedence Executable  {0}", pc.PrecedenceExecutable);  
                Console.WriteLine("Value                  {0}", pc.Value);  
                Console.WriteLine("-----------------------------------");  
            }  
            Executables seqExecs = seq.Executables;  
            int numExecs = seqExecs.Count;  
            Console.WriteLine("Number of Executables in Sequence: {0}", numExecs);  
        }  
    }  
}  
Imports System  
Imports System.Collections.Generic  
Imports System.Text    
Imports Microsoft.SqlServer.Dts.Runtime  
Imports Microsoft.SqlServer.Dts.Tasks. FileSystemTask  

Namespace Sequence_API  
    Class Program  
        Shared  Sub Main(ByVal args() As String)  
            Dim package As Package =  New Package()   
            Dim seq As Sequence = CType(package.Executables.Add("STOCK:SEQUENCE"), Sequence)  

            ' Add a File System task.  
            Dim eFileTask1 As Executable =  seq.Executables.Add("STOCK:FileSystemTask")   
            Dim thFileTask1 As TaskHost =  eFileTask1 as TaskHost   

            ' Add a second File System task.  
            Dim eFileTask2 As Executable =  seq.Executables.Add("STOCK:FileSystemTask")   
            Dim thFileTask2 As TaskHost =  eFileTask2 as TaskHost   

            ' Add a Bulk Insert task.  
            Dim eBulkInsert As Executable =  seq.Executables.Add("STOCK:BulkInsertTask")   
            Dim thBulkInsert As TaskHost =  eBulkInsert as TaskHost   

            ' Add a precedence contraint between eFileTask1 and eFileTask2.  
            ' Set the constraint to be that eFileTask2 cannot run   
            ' until eFileTask1 completes.  
            Dim pcFileTasks As PrecedenceConstraint =  seq.PrecedenceConstraints.Add(eFileTask1,eFileTask2)   

            ' Add another precedence contraint. Add it between eFileTask2 and BulkInsert.  
            ' Again, set the constraint to be that BulkInsert cannot run   
            ' until eFileTask2 completes.  
            Dim pcFiletoBulk As PrecedenceConstraint =  seq.PrecedenceConstraints.Add(eFileTask2,eBulkInsert)   
            ' Obtain the precedence constraint collection, and display properties.  
            ' Some properties are read/write and have not been set.  
            Dim seqPCs As PrecedenceConstraints =  seq.PrecedenceConstraints   
            Dim numPCs As Integer =  seqPCs.Count   
            Console.WriteLine("Number of precedence constraints in Sequence: {0}", numPCs)  
            Console.WriteLine("----------------------------------------")  

            Dim pc As PrecedenceConstraint  
            For Each pc In seqPCs  
                Console.WriteLine("Constrained container  {0}", pc.ConstrainedExecutable)  
                Console.WriteLine("Description            {0}", pc.Description)  
                Console.WriteLine("Evaluation operation   {0}", pc.EvalOp)  
                Console.WriteLine("Evaluates true         {0}", pc.EvaluatesTrue)  
                Console.WriteLine("ID                     {0}", pc.ID)  
                Console.WriteLine("LogicalAnd             {0}", pc.LogicalAnd)  
                Console.WriteLine("Name                   {0}", pc.Name)  
                Console.WriteLine("Precedence Executable  {0}", pc.PrecedenceExecutable)  
                Console.WriteLine("Value                  {0}", pc.Value)  
                Console.WriteLine("-----------------------------------")  
            Next  
            Dim seqExecs As Executables =  seq.Executables   
            Dim numExecs As Integer =  seqExecs.Count   
            Console.WriteLine("Number of Executables in Sequence: {0}", numExecs)  
        End Sub  
    End Class  
End Namespace  

Beispielausgabe:

Anzahl der Vorrangeinschränkungen in Sequenz: 2

----------------------------------------

Eingeschränkter Container Microsoft.SqlServer.Dts.Runtime.TaskHost

Beschreibung

Einschränkung des Auswertungsvorgangs

Wertet true true aus.

ID {A4F5C0E6-A9A6-470D-9646-7FEAFE3B45AD}

LogicalAnd True

Name {A4F5C0E6-A9A6-470D-9646-7FEAFE3B45AD}

Rangfolge ausführbarer Microsoft.SqlServer.Dts.Runtime.TaskHost

Werterfolg

-----------------------------------

Eingeschränkter Container Microsoft.SqlServer.Dts.Runtime.TaskHost

Beschreibung

Einschränkung des Auswertungsvorgangs

Wertet true true aus.

ID {665C52DE-232A-4593-ADF1-7C51949712B8}

LogicalAnd True

Name {665C52DE-232A-4593-ADF1-7C51949712B8}

Rangfolge ausführbarer Microsoft.SqlServer.Dts.Runtime.TaskHost

Werterfolg

-----------------------------------

Anzahl der ausführbaren Dateien in Sequenz: 3

Hinweise

Vorrangsbeschränkungen verknüpfen Container und Aufgaben in einen sortierten Workflow. Sie können Vorrangeinschränkungen zwischen allen Arten von Containern und Vorgängen implementieren, außer Paketen. Weitere Informationen finden Sie unter Rangfolgeneinschränkungen.

Gilt für: