LogProvider.GetExpression(String) Método

Definición

Espacio de nombres:

Microsoft.SqlServer.Dts.Runtime

Ensamblado:

Microsoft.SqlServer.ManagedDTS.dll

Devuelve una cadena que contiene la expresión de la propiedad especificada. Null significa que no se asigna ninguna expresión.

public:
 virtual System::String ^ GetExpression(System::String ^ propertyName);

public string GetExpression (string propertyName);

abstract member GetExpression : string -> string
override this.GetExpression : string -> string

Public Function GetExpression (propertyName As String) As String

Parámetros

propertyName

String

El nombre de la propiedad cuya expresión desea ver.

Devoluciones

String

Cadena que contiene la expresión usada para evaluar la propiedad .

Implementaciones

GetExpression(String)

Ejemplos

En el ejemplo siguiente se establece la propiedad Description del proveedor de registro para que sea el texto "This is the log for..." con el mes actual y el día anexados al final de la cadena. A continuación, valida el paquete, que resuelve la expresión y guarda el valor en la propiedad especificada en propertyName. La expresión también se establecerá en las expresiones de la propiedad cuando se guarde el paquete.

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

namespace LogProvider_Expression_Tests  
{  
    class Program  
    {  
        static void Main(string[] args)  
        {  
            // The package is one of the SSIS Samples. The package was  
            // modified to log to the SSIS log provider for Text files  
            // and saved before loading into this code.  

            string mySample = @"C:\Program Files\Microsoft SQL Server\100\Samples\Integration Services\Package Samples\ExecuteProcess Sample\ExecuteProcess\UsingExecuteProcess.dtsx";  

            // Create the Application, and load the sample.  
            Application app = new Application();  
            Package pkg = app.LoadPackage(mySample, null);  

            // Get the LogProviders collection.  
            LogProviders logProvs = pkg.LogProviders;  

            // Get the "SSIS log provider for Text files"  
            // provider from the collection.  
            LogProvider textLogProv = logProvs["SSIS log provider for Text files"];  

            //Display the current description of this provider.  
            String currDescription = textLogProv.Description;  
            Console.WriteLine("Current description: {0}", currDescription);  

            // Set an expression. Only a few properties  
            // are available to have expressions. For Log Providers,   
            //current only the properties of ConfigString, Description,  
            // and Name take expressions.  
            DateTime dt = DateTime.Now;  
            String nowMonth = dt.ToString("m");  
            String newDesc = "\"This is the log for " + nowMonth + "\"";  
            textLogProv.SetExpression("Description", newDesc);  

            // Validate the package to set the expression  
            // onto the property.  
            Connections pkgConns = pkg.Connections;            
            DTSExecResult valResult = pkg.Validate(pkgConns, null, null, null);  
            if (valResult != DTSExecResult.Failure)  
            {  
                Console.WriteLine("Validation passed: {0}", valResult);  
            }  
            else  
                Console.WriteLine("Validation FAILED: {0}", valResult);  

            // Retrieve the log provider collections.  
            logProvs = pkg.LogProviders;  

            // Retreive the text log provider from the collection.  
            textLogProv = logProvs["SSIS log provider for Text files"];  

            // Check the expression, and verify that the name changed.  
            String logProvExpr = textLogProv.GetExpression("Description");  
            Console.WriteLine("The expression for Description is {0}", logProvExpr);  
            String newDescAfter = textLogProv.Description;  
            Console.WriteLine("The description is now: {0}", newDescAfter);  
        }  
    }  
}  

Imports System  
Imports System.Collections.Generic  
Imports System.Text  
Imports Microsoft.SqlServer.Dts.Runtime  

Namespace LogProvider_Expression_Tests  
    Class Program  
        Shared  Sub Main(ByVal args() As String)  
        ' The package is one of the SSIS Samples. The package was  
        ' modified to log to the SSIS log provider for Text files  
        ' and saved before loading into this code.  
        Dim mySample As String = "C:\Program Files\Microsoft SQL Server\100\Samples\Integration Services\Package Samples\ExecuteProcess Sample\ExecuteProcess\UsingExecuteProcess.dtsx"  

        ' Create the Application, and load the sample.  
        Dim app As New Application()  
        Dim pkg As Package = app.LoadPackage(mySample, Nothing)  

        ' Get the LogProviders collection.  
        Dim logProvs As LogProviders = pkg.LogProviders  

        ' Get the "SSIS log provider for Text files"  
        ' provider from the collection.  
        Dim textLogProv As LogProvider = logProvs("SSIS log provider for Text files")  

        'Display the current description of this provider.  
        Dim currDescription As String = textLogProv.Description  
        Console.WriteLine("Current description: {0}", currDescription)  

        ' Set an expression. Only a few properties  
        ' are available to have expressions. For Log Providers,   
        'current only the properties of ConfigString, Description,  
        ' and Name take expressions.  
        Dim dt As DateTime = DateTime.Now  
        Dim nowMonth As String = dt.ToString("m")  
        Dim newDesc As String = """This is the log for " + nowMonth + """"  
        textLogProv.SetExpression("Description", newDesc)  

        ' Validate the package to set the expression  
        ' onto the property.  
        Dim pkgConns As Connections = pkg.Connections  
        Dim valResult As DTSExecResult = pkg.Validate(pkgConns, Nothing, Nothing, Nothing)  
        If valResult <> DTSExecResult.Failure Then  
            Console.WriteLine("Validation passed: {0}", valResult)  
        Else  
            Console.WriteLine("Validation FAILED: {0}", valResult)  
        End If  
        ' Retrieve the log provider collections.  
        logProvs = pkg.LogProviders  

        ' Retreive the text log provider from the collection.  
        textLogProv = logProvs("SSIS log provider for Text files")  

        ' Check the expression, and verify that the name changed.  
        Dim logProvExpr As String = textLogProv.GetExpression("Description")  
        Console.WriteLine("The expression for Description is {0}", logProvExpr)  
        Dim newDescAfter As String = textLogProv.Description  
        Console.WriteLine("The description is now: {0}", newDescAfter)  
        End Sub  
    End Class  
End Namespace  

Salida de ejemplo:

Descripción actual: escribe entradas de registro para eventos en un archivo CSV.

Validación superada: Correcto

La expresión de Description es "This is the log for january 06" (Este es el registro del 06 de enero).

La descripción es ahora: Este es el registro del 06 de enero

Comentarios

propertyName será ConfigString, Description o Name. En el caso del proveedor de registro, actualmente son las únicas tres propiedades que pueden usar una expresión.