DTSBufferManagerClass.FindColumnByLineageID Method

Articolo
12/15/2008

Gets the location of a column in the specified IDTSBuffer90 object.

Spazio dei nomi: Microsoft.SqlServer.Dts.Pipeline.Wrapper
Assembly : Microsoft.SqlServer.DTSPipelineWrap (in microsoft.sqlserver.dtspipelinewrap.dll)

Sintassi

'Dichiarazione
<DispIdAttribute(121)> _
Public Overridable Function FindColumnByLineageID ( _
    <InAttribute> hBufferType As Integer, _
    <InAttribute> nLineageID As Integer _
) As Integer Implements IDTSBufferManager90.FindColumnByLineageID

[DispIdAttribute(121)] 
public virtual int IDTSBufferManager90.FindColumnByLineageID (
    [InAttribute] int hBufferType,
    [InAttribute] int nLineageID
)

[DispIdAttribute(121)] 
public:
virtual int FindColumnByLineageID (
    [InAttribute] int hBufferType, 
    [InAttribute] int nLineageID
) = IDTSBufferManager90::FindColumnByLineageID

J# non supporta la dichiarazione di nuove implementazioni di interfacce esplicite ma ne supporta l'utilizzo.

JScript non supporta la dichiarazione di nuove implementazioni di interfacce esplicite ma ne supporta l'utilizzo.

Parametri

hBufferType
The ID of the IDTSBuffer90 object that contains the column.

nLineageID
The lineage ID of the column to locate in the IDTSBuffer90.

Valore restituito

An Integer that indicates the location, by index, of the column in the IDTSBuffer90.

Osservazioni

This method locates the column of an IDTSInput90 or IDTSOutput90 in the specified IDTSBuffer90. This method is necessary because an instance of a buffer contains all of the IDTSOutputColumn90 objects defined in the IDTSOutputColumnCollection90 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.

Esempio

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()
{
    IDTSInput90 input = ComponentMetaData.InputCollection[0];
    bufferColumnIndex = new int[BufferManager.GetColumnCount(input.Buffer)];

    for( int col=0; col < input.InputColumnCollection.Count; col++)
    {
        IDTSInputColumn90 iCol = input.InputColumnCollection[col];
        bufferColumnIndex[col] = BufferManager.FindColumnByLineageID(input.Buffer, iCol.LineageID);
    }
}

Private bufferColumnIndex As Integer() 

Public Overloads Overrides Sub PreExecute() 
 Dim input As IDTSInput90 = ComponentMetaData.InputCollection(0) 
 bufferColumnIndex = New Integer(BufferManager.GetColumnCount(input.Buffer) - 1) {} 
 Dim col As Integer = 0 
 While col < input.InputColumnCollection.Count 
   Dim iCol As IDTSInputColumn90 = input.InputColumnCollection(col) 
   bufferColumnIndex(col) = BufferManager.FindColumnByLineageID(input.Buffer, iCol.LineageID) 
   col -= 1 
 End While 
End Sub

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.

Piattaforme

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Per un elenco delle piattaforme supportate, vedere Requisiti hardware e software per l'Installazione di SQL Server 2005.

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