IDTSBufferManager100.FindColumnByLineageID Method
Gets the ___location, by index, of a column in a specified IDTSBuffer100 object.
Namespace: Microsoft.SqlServer.Dts.Pipeline.Wrapper
Assembly: Microsoft.SqlServer.DTSPipelineWrap (in Microsoft.SqlServer.DTSPipelineWrap.dll)
Syntax
'Declaration
Function FindColumnByLineageID ( _
hBufferType As Integer, _
nLineageID As Integer _
) As Integer
'Usage
Dim instance As IDTSBufferManager100
Dim hBufferType As Integer
Dim nLineageID As Integer
Dim returnValue As Integer
returnValue = instance.FindColumnByLineageID(hBufferType, _
nLineageID)
int FindColumnByLineageID(
int hBufferType,
int nLineageID
)
int FindColumnByLineageID(
[InAttribute] int hBufferType,
[InAttribute] int nLineageID
)
abstract FindColumnByLineageID :
hBufferType:int *
nLineageID:int -> int
function FindColumnByLineageID(
hBufferType : int,
nLineageID : int
) : int
Parameters
- hBufferType
Type: System.Int32
The ID of the IDTSBuffer100 object that contains the column.
- nLineageID
Type: System.Int32
The lineage ID of the column to locate in the IDTSBuffer100.
Return Value
Type: System.Int32
An integer that indicates the ___location, by index, of the column in the IDTSBuffer100.
Remarks
This method locates the column of an IDTSInput100 or IDTSOutput100 in the specified IDTSBuffer100. This method is necessary because an instance of a buffer contains all of the IDTSOutputColumn100 objects defined in the IDTSOutputColumnCollection100 collections of the components in a graph. Components cannot rely on using the index ___location of its output column, or input column, as the index of that column in a buffer row. Because of this, components must use FindColumnByLineageID to locate the columns in the buffer.
Examples
The following code example shows how a transformation component that does not have output columns uses the FindColumnByLineageID to locate its input columns in the buffer.
int[] bufferColumnIndex;
public override void PreExecute()
{
IDTSInput100 input = ComponentMetaData.InputCollection[0];
bufferColumnIndex = new int[BufferManager.GetColumnCount(input.Buffer)];
for( int col=0; col < input.InputColumnCollection.Count; col++)
{
IDTSInputColumn100 iCol = input.InputColumnCollection[col];
bufferColumnIndex[col] = BufferManager.FindColumnByLineageID(input.Buffer, iCol.LineageID);
}
}
Private bufferColumnIndex As Integer()
Public Overloads Overrides Sub PreExecute()
Dim input As IDTSInput100 = ComponentMetaData.InputCollection(0)
bufferColumnIndex = New Integer(BufferManager.GetColumnCount(input.Buffer) - 1) {}
Dim col As Integer = 0
While col < input.InputColumnCollection.Count
Dim iCol As IDTSInputColumn100 = input.InputColumnCollection(col)
bufferColumnIndex(col) = BufferManager.FindColumnByLineageID(input.Buffer, iCol.LineageID)
col -= 1
End While
End Sub