IDTSBufferManager90.FindColumnByLineageID Method

Gets the location, by index, of a column in a specified IDTSBuffer90 object.

命名空间: Microsoft.SqlServer.Dts.Pipeline.Wrapper
程序集: Microsoft.SqlServer.DTSPipelineWrap (in microsoft.sqlserver.dtspipelinewrap.dll)

语法

声明
<DispIdAttribute(121)> _
Function FindColumnByLineageID ( _
    <InAttribute> hBufferType As Integer, _
    <InAttribute> nLineageID As Integer _
) As Integer

[DispIdAttribute(121)] 
int FindColumnByLineageID (
    [InAttribute] int hBufferType,
    [InAttribute] int nLineageID
)

[DispIdAttribute(121)] 
int FindColumnByLineageID (
    [InAttribute] int hBufferType, 
    [InAttribute] int nLineageID
)

/** @attribute DispIdAttribute(121) */ 
int FindColumnByLineageID (
    /** @attribute InAttribute() */ int hBufferType, 
    /** @attribute InAttribute() */ int nLineageID
)

DispIdAttribute(121) 
function FindColumnByLineageID (
    hBufferType : int, 
    nLineageID : int
) : int

参数

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

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

返回值

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

备注

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 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.

示例

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()
{
    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

线程安全

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.

平台

开发平台

有关支持的平台列表，请参阅安装 SQL Server 2005 的硬件和软件要求。

目标平台

有关支持的平台列表，请参阅安装 SQL Server 2005 的硬件和软件要求。

请参阅

参考

IDTSBufferManager90 Interface
IDTSBufferManager90 Members
Microsoft.SqlServer.Dts.Pipeline.Wrapper Namespace