Interfaccia IDTSVirtualInput100
Represents the columns available to a component from the upstream component.
Spazio dei nomi Microsoft.SqlServer.Dts.Pipeline.Wrapper
Assembly: Microsoft.SqlServer.DTSPipelineWrap (in Microsoft.SqlServer.DTSPipelineWrap.dll)
Sintassi
'Dichiarazione
<GuidAttribute("9944F684-49C4-4354-AB7F-EE422A650E0E")> _
Public Interface IDTSVirtualInput100 _
Inherits IDTSObject100
'Utilizzo
Dim instance As IDTSVirtualInput100
[GuidAttribute("9944F684-49C4-4354-AB7F-EE422A650E0E")]
public interface IDTSVirtualInput100 : IDTSObject100
[GuidAttribute(L"9944F684-49C4-4354-AB7F-EE422A650E0E")]
public interface class IDTSVirtualInput100 : IDTSObject100
[<GuidAttribute("9944F684-49C4-4354-AB7F-EE422A650E0E")>]
type IDTSVirtualInput100 =
interface
interface IDTSObject100
end
public interface IDTSVirtualInput100 extends IDTSObject100
Nel tipo IDTSVirtualInput100 sono esposti i membri seguenti.
Proprietà
Nome | Descrizione | |
---|---|---|
Description | Gets or sets the description of an IDTSVirtualInput100 object. | |
ID | Gets or sets the ID of a virtual input object. | |
IdentificationString | Gets a string that uniquely identifies the IDTSVirtualInput100. | |
IsSorted | Gets a value that indicates whether the virtual input columns in the IDTSVirtualInput100 are sorted. | |
Name | Gets or sets the name of an IDTSVirtualInput100. | |
ObjectType | Gets the DTSObjectType of an IDTSVirtualInput100. | |
SourceLocale | Gets the locale ID (LCID) of the source of the IDTSVirtualInput100. | |
VirtualInputColumnCollection | Gets the IDTSVirtualInputColumnCollection100 of an IDTSVirtualInput100. |
In alto
Metodi
Nome | Descrizione | |
---|---|---|
SetUsageType | Maps a virtual input column object and sets its usage type. |
In alto
Osservazioni
The IDTSVirtualInput100 is retrieved by calling the GetVirtualInput method of an IDTSInput100 object. The VirtualInputColumnCollection property contains the columns that are available from the upstream components in the graph.
When programmatically building a data flow task, the virtual columns are selected for a component by calling the SetUsageType method of the CManagedComponentWrapperClass.
Developers writing custom data flow components use the virtual input to discover the available upstream columns, and, depending on the component, to add columns to the input based on the columns in the virtual collection.
Because the virtual input is a reflection of upstream columns, modifications to the virtual input or the columns in the virtual input collection do not have any impact on the IDTSOutput100 itself.
Esempi
The following code example shows how to use the virtual input to select the columns used by a component when programmatically building the data flow task.
public void SelectColumns(IDTSComponentMetaData100 md)
{
// Create the design time instance of the component.
CManagedComponentWrapper wrp = md.Instantiate();
// Walk the input collection.
foreach (IDTSInput100 input in md.InputCollection)
{
// Get the virtual input columns.
IDTSVirtualInput100 vInput = input.GetVirtualInput();
// For each virtual column, set its usagetype to READONLY.
foreach (IDTSVirtualInputColumn100 vCol in vInput.VirtualInputColumnCollection)
wrp.SetUsageType(input.ID, vInput, vCol.LineageID, DTSUsageType.UT_READONLY);
}
}
Public Sub SelectColumns(ByVal md As IDTSComponentMetaData100)
Dim wrp As CManagedComponentWrapper = md.Instantiate
For Each input As IDTSInput100 In md.InputCollection
Dim vInput As IDTSVirtualInput100 = input.GetVirtualInput
For Each vCol As IDTSVirtualInputColumn100 In vInput.VirtualInputColumnCollection
wrp.SetUsageType(input.ID, vInput, vCol.LineageID, DTSUsageType.UT_READONLY)
Next
Next
End Sub
The following code example shows a custom data flow component that selects all of the DT_STR columns from the virtual input when the input is connected to a path.
public override void OnInputPathAttached(int inputID)
{
IDTSInput100 input = ComponentMetaData.InputCollection.GetObjectByID(inputID);
IDTSVirtualInput100 vInput = input.GetVirtualInput();
foreach (IDTSVirtualInputColumn100 vCol in vInput.VirtualInputColumnCollection)
{
if (vCol.DataType == DataType.DT_STR)
{
this.SetUsageType(inputID, vInput, vCol.LineageID, DTSUsageType.UT_READONLY);
}
}
}
Public Overrides Sub OnInputPathAttached(ByVal inputID As Integer)
Dim input As IDTSInput100 = ComponentMetaData.InputCollection.GetObjectByID(inputID)
Dim vInput As IDTSVirtualInput100 = input.GetVirtualInput
For Each vCol As IDTSVirtualInputColumn100 In vInput.VirtualInputColumnCollection
If vCol.DataType = DataType.DT_STR Then
Me.SetUsageType(inputID, vInput, vCol.LineageID, DTSUsageType.UT_READONLY)
End If
Next
End Sub