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IDTSVirtualInput100 Interface

Represents the columns available to a component from the upstream component.

Namespace:  Microsoft.SqlServer.Dts.Pipeline.Wrapper
Assembly:  Microsoft.SqlServer.DTSPipelineWrap (in Microsoft.SqlServer.DTSPipelineWrap.dll)

[TypeLibTypeAttribute(TypeLibTypeFlags.FDual|TypeLibTypeFlags.FDispatchable)]
[GuidAttribute("DD9E7F1F-A112-4EBD-9178-EE7DB0F2EDEC")]
public interface IDTSVirtualInput100 : IDTSObject100

The IDTSVirtualInput100 type exposes the following members.

  NameDescription
Public propertyDescriptionGets or sets the description of an IDTSVirtualInput100 object.
Public propertyIDGets or sets the ID of a virtual input object.
Public propertyIdentificationStringGets a string that uniquely identifies the IDTSVirtualInput100.
Public propertyIsSortedGets a value that indicates whether the virtual input columns in the IDTSVirtualInput100 are sorted.
Public propertyNameGets or sets the name of an IDTSVirtualInput100.
Public propertyObjectTypeGets the DTSObjectType of an IDTSVirtualInput100.
Public propertySourceLocaleGets the locale ID (LCID) of the source of the IDTSVirtualInput100.
Public propertyVirtualInputColumnCollectionGets the IDTSVirtualInputColumnCollection100 of an IDTSVirtualInput100.
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  NameDescription
Public methodSetUsageTypeMaps a virtual input column object and sets its usage type.
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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.

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);
    }
}

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);
        }
    }
}
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