ConnectionManager.GetExpression Method

Artigo
12/03/2008

Returns a String that contains the expression for the specified property. Null means that no expression has been assigned.

Namespace: Microsoft.SqlServer.Dts.Runtime
Assembly: Microsoft.SqlServer.ManagedDTS (in microsoft.sqlserver.manageddts.dll)

Syntax

'Declaration
Public Function GetExpression ( _
    propertyName As String _
) As String

public string GetExpression (
    string propertyName
)

public:
virtual String^ GetExpression (
    String^ propertyName
) sealed

public final String GetExpression (
    String propertyName
)

public final function GetExpression (
    propertyName : String
) : String

Parameters

propertyName
The name of the property whose expression you want to see.

Return Value

A String that contains the expression used to evaluate the property.

Remarks

The propertyName can be a connection string, description, name, or protection level. For the connection manager, these are currently the only properties that support expressions.

Besides those common connection manager properties, each connection type has properties that are unique. These properties are listed by the Properties collection.

Example

The following code example sets an expression on a unique property of the connection manager, and then retrieves it after the package is validated.

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\90\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 on the property.
            DTSExecResult valResult = pkg.Validate(myConns, null, null, null);
            
            // Now that the value has been set, retrieve the value
            // and the expression.
            myValue = myConnMgr.Properties["RetainSameConnection"].GetValue(myConnMgr);
            mySValue = myValue.ToString();
            String myExpression = myConnMgr.Properties["RetainSameConnection"].GetExpression(myConnMgr);
            String mySExpression = myExpression.ToString();
            Console.WriteLine("value and expression is {0}, {1}", mySValue, mySExpression); 
        }
    }
}

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\90\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 on the property.
        Dim valResult As DTSExecResult = pkg.Validate(myConns, Nothing, Nothing, Nothing)

        ' Now that the value has been set, retrieve the value
        ' and the expression.
        myValue = myConnMgr.Properties("RetainSameConnection").GetValue(myConnMgr)
        mySValue = myValue.ToString()
        Dim myExpression As String = myConnMgr.Properties("RetainSameConnection").GetExpression(myConnMgr)
        Dim mySExpression As String = myExpression.ToString()
        Console.WriteLine("value and expression is {0}, {1}", mySValue, mySExpression) 
        End Sub
    End Class
End Namespace

Sample Output:

has RetainSameConnection? True

value before is False

value and expression is True, true

Thread Safety

Any public static (Shared in Microsoft Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Platforms

Development Platforms

For a list of the supported platforms, see Hardware and Software Requirements for Installing SQL Server 2005.

Target Platforms