DTSPrecedenceEvalOp Enum

Definisi

Ruang nama:

Microsoft.SqlServer.Dts.Runtime

Rakitan:

Microsoft.SqlServer.ManagedDTS.dll

Menunjukkan operasi evaluasi yang digunakan batasan prioritas.

public enum class DTSPrecedenceEvalOp

public enum DTSPrecedenceEvalOp

type DTSPrecedenceEvalOp = 

Public Enum DTSPrecedenceEvalOp

Warisan

Enum

DTSPrecedenceEvalOp

Bidang

Constraint	2	Menentukan bahwa hasil eksekusi menentukan apakah kontainer atau tugas yang dibatasi berjalan. Atur Value properti ke nilai yang PrecedenceConstraint diinginkan dari DTSExecResult enumerasi.
Expression	1	Menentukan bahwa nilai ekspresi menentukan apakah kontainer atau tugas yang dibatasi berjalan. Atur Expression properti dari PrecedenceConstraint.
ExpressionAndConstraint	3	Menentukan bahwa hasil batasan harus terjadi dan ekspresi harus mengevaluasi kontainer atau tugas yang dibatasi untuk dijalankan. Atur properti Value dan Expression dari PrecedenceConstraint, dan atur propertinya LogicalAnd ke true.
ExpressionOrConstraint	4	Menentukan bahwa hasil batasan harus terjadi, atau ekspresi harus mengevaluasi, agar kontainer atau tugas yang dibatasi dapat dijalankan. Atur Value properti dan Expression dari PrecedenceConstraint, dan atur propertinya LogicalAnd ke false.

Contoh

Contoh kode berikut membuat tiga tugas, dan menempatkan batasan prioritas di antaranya. PrecedenceConstraints Dengan menggunakan koleksi, ini melakukan iterasi atas batasan dalam paket, menampilkan informasi tentang setiap batasan, termasuk EvalOp properti , yang berisi salah satu nilai dari enumerasi ini. Contoh kode kemudian mengubah nilai penggunaan EvalOp enumerasi ini.

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

namespace PrecedenceConst  
{  
    class Program  
    {  
        static void Main(string[] args)  
        {  
            Package pkg = new Package();  
            // Add a File System task.  
            Executable eFileTask1 = pkg.Executables.Add("STOCK:FileSystemTask");  
            TaskHost thFileTask1 = eFileTask1 as TaskHost;  

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

            // Add a Bulk Insert task.  
            Executable eBulkInsert = pkg.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 = pkg.PrecedenceConstraints.Add(eFileTask1, eFileTask2);  
            pcFileTasks.Name = "constraint between File System Tasks";  

            // 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 = pkg.PrecedenceConstraints.Add(eFileTask2, eBulkInsert);  
            pcFileTasks.Name = "constraint between File System and Bulk Insert Tasks";  

            // Obtain the precedence constraint collection.  
            PrecedenceConstraints pConsts = pkg.PrecedenceConstraints;  
            Boolean containsConstraint = pkg.PrecedenceConstraints.Contains("constraint between File System and Bulk Insert Tasks");  
            Console.WriteLine("Contains the constraint between File System and Bulk Insert Tasks? {0}", containsConstraint);  

            foreach (PrecedenceConstraint pc in pConsts)  
            {  
                Console.WriteLine("Constrained container  {0}", pc.ConstrainedExecutable);  
                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("Precedence Executable  {0}", pc.PrecedenceExecutable);  
                Console.WriteLine("-----------------------------------");  
            }  

            // Set the EvalOp of the first constraint using the DtsPrecedenceEvalOp enumerator.  
            PrecedenceConstraint firstPC = pConsts[0];  
            firstPC.EvalOp = DTSPrecedenceEvalOp.Expression;  
            Console.WriteLine("Evaluation operation after {0}", firstPC.EvalOp);  
        }  
    }  
}  

Imports System  
Imports System.Collections.Generic  
Imports System.Text  
Imports Microsoft.SqlServer.Dts.Runtime  
Imports Microsoft.SqlServer.Dts.Tasks.BulkInsertTask  
Imports Microsoft.SqlServer.Dts.Tasks.FileSystemTask  

Namespace PrecedenceConst  
    Class Program  
        Shared  Sub Main(ByVal args() As String)  
            Dim pkg As Package =  New Package()   
            ' Add a File System task.  
            Dim eFileTask1 As Executable =  pkg.Executables.Add("STOCK:FileSystemTask")   
            Dim thFileTask1 As TaskHost =  eFileTask1 as TaskHost   

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

            ' Add a Bulk Insert task.  
            Dim eBulkInsert As Executable =  pkg.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 =  pkg.PrecedenceConstraints.Add(eFileTask1,eFileTask2)   
            pcFileTasks.Name = "constraint between File System Tasks"  

            ' 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 =  pkg.PrecedenceConstraints.Add(eFileTask2,eBulkInsert)   
            pcFileTasks.Name = "constraint between File System and Bulk Insert Tasks"  

            ' Obtain the precedence constraint collection.  
            Dim pConsts As PrecedenceConstraints =  pkg.PrecedenceConstraints   
            Dim containsConstraint As Boolean =  pkg.PrecedenceConstraints.Contains("constraint between File System and Bulk Insert Tasks")   
            Console.WriteLine("Contains the constraint between File System and Bulk Insert Tasks? {0}", containsConstraint)  

            Dim pc As PrecedenceConstraint  
            For Each pc In pConsts  
                Console.WriteLine("Constrained container  {0}", pc.ConstrainedExecutable)  
                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("Precedence Executable  {0}", pc.PrecedenceExecutable)  
                Console.WriteLine("-----------------------------------")  
            Next  

            ' Set the EvalOp of the first constraint using the DtsPrecedenceEvalOp enumerator.  
            Dim firstPC As PrecedenceConstraint =  pConsts(0)   
            firstPC.EvalOp = DTSPrecedenceEvalOp.Expression  
            Console.WriteLine("Evaluation operation after {0}", firstPC.EvalOp)  
        End Sub  
    End Class  
End Namespace  

Contoh Output:

Contains the constraint between File System and Bulk Insert Tasks? True

Constrained container Microsoft.SqlServer.Dts.Runtime.TaskHost

Evaluation operation Constraint

Evaluates true True

ID {0EDDD5B8-7135-4A73-B240-EDF54C0E66AC}

LogicalAnd True

Precedence Executable Microsoft.SqlServer.Dts.Runtime.TaskHost

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

Constrained container Microsoft.SqlServer.Dts.Runtime.TaskHost

Evaluation operation Constraint

Evaluates true True

ID {80584B94-A3D0-4E08-B9C1-8CCC7BD7D086}

LogicalAnd True

Precedence Executable Microsoft.SqlServer.Dts.Runtime.TaskHost

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

Evaluation operation after Expression

Keterangan

Item prioritas adalah tugas atau kontainer yang ekspresi atau hasil eksekusinya (penyelesaian, keberhasilan, atau kegagalan) menentukan apakah tugas atau kontainer berikutnya, item yang dibatasi, berjalan. Nilai defaultnya adalah Constraint. Untuk informasi selengkapnya, lihat Batasan Prioritas.