Condividi tramite

  • Articolo

Metodo SetExpression

Assigns the specified expression to the property. Specify nullNothingnullptrunitriferimento Null (Nothing in Visual Basic). to remove an existing expression from the property.

Spazio dei nomi:  Microsoft.SqlServer.Dts.Runtime
Assembly:  Microsoft.SqlServer.ManagedDTS (in Microsoft.SqlServer.ManagedDTS.dll)

Sintassi

'Dichiarazione
Public Sub SetExpression ( _
    propertyName As String, _
    expression As String _
)
'Utilizzo
Dim instance As ConnectionManager
Dim propertyName As String
Dim expression As String

instance.SetExpression(propertyName, _
    expression)

public void SetExpression(
    string propertyName,
    string expression
)

public:
virtual void SetExpression(
    String^ propertyName, 
    String^ expression
) sealed

abstract SetExpression : 
        propertyName:string * 
        expression:string -> unit 
override SetExpression : 
        propertyName:string * 
        expression:string -> unit 

public final function SetExpression(
    propertyName : String, 
    expression : String
)

Parametri

Implementa

IDTSPropertiesProvider. . :: . .SetExpression(String, String)

Osservazioni

The propertyName for the connection manager object can be a connection string, description, name, or protection level. For the connection manager, those are currently the only properties that support expressions. Besides these common connection manager properties, each connection type has properties that are unique. These properties are listed by the Properties collection. You can use the SetExpression method to provide the name of the property to set as a String parameter. If you want to set properties that are unique to the connection by using the Properties collection, it may be useful to know that this properties collection inherits from DtsProperty. Notice that the SetExpression inherited from DtsProperty takes an Object as the first parameter, not a String.

Esempi

The following code example shows how to use an expression to set the value of a property that is specific to a connection manager. The properties unique to the connection manager are contained in the Properties collection.

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

namespace ConnMgr_Properties_Collection
{
    class Program
    {
        static void Main(string[] args)
        {
            // The package is one of the SSIS Samples.
            string mySample = @"C:\Program Files\Microsoft SQL Server\100\Samples\Integration Services\Package Samples\CalculatedColumns Sample\CalculatedColumns\CalculatedColumns.dtsx";

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

            // Get the Properties collection from the connection manager.
            ConnectionManager myConnMgr = myConns[0];
            DtsProperties connProperties = myConnMgr.Properties;

            // View information about the RetainSameConnection property
            // before setting it using the SetExpression method.
            Boolean hasProperty = connProperties.Contains("RetainSameConnection");
            Console.WriteLine("has RetainSameConnection? {0}", hasProperty);
            Object myValue = myConnMgr.Properties["RetainSameConnection"].GetValue(myConnMgr);
            String mySValue = myValue.ToString();
            Console.WriteLine("value before is {0}", mySValue);String myTrueString = "true";

            // Use SetExpression to set the value to true.
            myConnMgr.Properties["RetainSameConnection"].SetExpression(myConnMgr, myTrueString);
            
            // Validate the package to set the expression onto the property.
            DTSExecResult valResult = pkg.Validate(myConns, null, null, null);
            
            // Now that the value has been set, retrieve it.
            myValue = myConnMgr.Properties["RetainSameConnection"].GetValue(myConnMgr);
            mySValue = myValue.ToString();
            Console.WriteLine("value after is {0}", mySValue); 
        }
    }
}

Imports System
Imports System.Collections.Generic
Imports System.Text
Imports Microsoft.SqlServer.Dts.Runtime
 
Namespace ConnMgr_Properties_Collection
    Class Program
        Shared  Sub Main(ByVal args() As String)
        ' The package is one of the SSIS Samples.
        Dim mySample As String = "C:\Program Files\Microsoft SQL Server\100\Samples\Integration Services\Package Samples\CalculatedColumns Sample\CalculatedColumns\CalculatedColumns.dtsx"
        
        ' Create an application and load the sample.
        Dim app As New Application()
        Dim pkg As Package = app.LoadPackage(mySample, Nothing)
        Dim myConns As Connections = pkg.Connections
        
        ' Get the Properties collection from the connection manager.
        Dim myConnMgr As ConnectionManager = myConns(0)
        Dim connProperties As DtsProperties = myConnMgr.Properties
        
        ' View information about the RetainSameConnection property
        ' before setting it using the SetExpression method.
        Dim hasProperty As [Boolean] = connProperties.Contains("RetainSameConnection")
        Console.WriteLine("has RetainSameConnection? {0}", hasProperty)
        Dim myValue As [Object] = myConnMgr.Properties("RetainSameConnection").GetValue(myConnMgr)
        Dim mySValue As String = myValue.ToString()
        Console.WriteLine("value before is {0}", mySValue)
        Dim myTrueString As String = "true"
        
        ' Use SetExpression to set the value to true.
        myConnMgr.Properties("RetainSameConnection").SetExpression(myConnMgr, myTrueString)
        
        ' Validate the package to set the expression onto the property.
        Dim valResult As DTSExecResult = pkg.Validate(myConns, Nothing, Nothing, Nothing)
        
        ' Now that the value has been set, retrieve it.
        myValue = myConnMgr.Properties("RetainSameConnection").GetValue(myConnMgr)
        mySValue = myValue.ToString()
        Console.WriteLine("value after is {0}", mySValue)
        End Sub
    End Class
End Namespace

Sample Output:

has RetainSameConnection? True

value before is False

value after is True