DTSBufferManagerClass.FindColumnByLineageID(Int32, Int32) DTSBufferManagerClass.FindColumnByLineageID(Int32, Int32) DTSBufferManagerClass.FindColumnByLineageID(Int32, Int32) Method

Definition

Gets the location of a column in the specified IDTSBuffer100 object.

public:
 virtual int FindColumnByLineageID(int hBufferType, int nLineageID) = Microsoft::SqlServer::Dts::Pipeline::Wrapper::IDTSBufferManager100::FindColumnByLineageID;
public virtual int FindColumnByLineageID (int hBufferType, int nLineageID);
Public Overridable Function FindColumnByLineageID (hBufferType As Integer, nLineageID As Integer) As Integer
Parameters
hBufferType
Int32 Int32 Int32

The ID of the IDTSBuffer100 object that contains the column.

nLineageID
Int32 Int32 Int32

The lineage ID of the column to locate in the IDTSBuffer100.

Returns

An Integer that indicates the location, by index, of the column in the IDTSBuffer100.

Implements

Examples

The following code example shows how a transformation component that does not have output columns uses 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  

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 of the components in a graph. Components cannot rely on using the index location of an output column or input column as the index of that column in a buffer row. Because of this, components must use the FindColumnByLineageID method to locate the columns in the buffer.

Applies to