Sélection de colonnes d'entrée par programme
Après avoir connecté des composants par programme, sélectionnez les colonnes des composants en amont que vous transformerez ou passerez aux composants en aval. Si vous ne sélectionnez pas de colonnes d'entrée pour votre composant, le composant ne reçoit pas de lignes de la part de la tâche de flux de données.
Sélection des colonnes
Appelez la méthode GetVirtualInput pour extraire la liste des colonnes disponibles d'un composant en amont, puis appelez la méthode SetUsageType de l'instance du composant au moment de la conception pour sélectionner des colonnes dans la collection de colonnes d'entrée virtuelle. Lorsque vous appelez cette méthode, le composant crée une colonne d'entrée dans sa collection de colonnes d'entrée dont l'ID de lignage est identique à la colonne correspondante dans la collection de sortie du composant en amont.
Ne sélectionnez pas de colonnes en appelant directement la méthode SetUsageType de l'objet d'entrée virtuel, parce que celle-ci passe outre la capacité du composant à rejeter des colonnes en raison de types de données ou d'autres propriétés inappropriés.
Exemple
L'exemple de code suivant montre comment utiliser l'instance au moment de la conception d'un composant pour sélectionner les colonnes d'un composant.
using System;
using Microsoft.SqlServer.Dts.Runtime;
using Microsoft.SqlServer.Dts.Pipeline;
using Microsoft.SqlServer.Dts.Pipeline.Wrapper;
namespace Microsoft.SqlServer.Dts.Samples
{
class Program
{
static void Main(string[] args)
{
// Create a package and add a Data Flow task.
Package package = new Package();
Executable e = package.Executables.Add("STOCK:PipelineTask");
TaskHost thMainPipe = e as TaskHost;
MainPipe dataFlowTask = thMainPipe.InnerObject as MainPipe;
// Add an OLE DB connection manager to the package.
ConnectionManager conMgr = package.Connections.Add("OLEDB");
conMgr.ConnectionString = "Provider=SQLOLEDB.1;" +
"Data Source=<servername>;Initial Catalog=AdventureWorks;" +
"Integrated Security=SSPI;";
conMgr.Name = "SSIS Connection Manager for OLE DB";
conMgr.Description = "OLE DB connection to the AdventureWorks database.";
// Create and configure an OLE DB source component.
IDTSComponentMetaData100 source =
dataFlowTask.ComponentMetaDataCollection.New();
source.ComponentClassID = "DTSAdapter.OleDbSource";
// Create the design-time instance of the source.
CManagedComponentWrapper srcDesignTime = source.Instantiate();
// The ProvideComponentProperties method creates a default output.
srcDesignTime.ProvideComponentProperties();
// Assign the connection manager.
source.RuntimeConnectionCollection[0].ConnectionManager =
DtsConvert.GetExtendedInterface(conMgr);
// Set the custom properties of the source.
srcDesignTime.SetComponentProperty("AccessMode", 2);
srcDesignTime.SetComponentProperty("SqlCommand",
"Select * from Production.Product");
// Connect to the data source,
// and then update the metadata for the source.
srcDesignTime.AcquireConnections(null);
srcDesignTime.ReinitializeMetaData();
srcDesignTime.ReleaseConnections();
// Create and configure an OLE DB destination.
IDTSComponentMetaData100 destination =
dataFlowTask.ComponentMetaDataCollection.New();
destination.ComponentClassID = "DTSAdapter.OleDbDestination";
// Create the design-time instance of the destination.
CManagedComponentWrapper destDesignTime = destination.Instantiate();
// The ProvideComponentProperties method creates a default input.
destDesignTime.ProvideComponentProperties();
// Create the path from source to destination.
IDTSPath100 path = dataFlowTask.PathCollection.New();
path.AttachPathAndPropagateNotifications(source.OutputCollection[0],
destination.InputCollection[0]);
// Get the destination's default input and virtual input.
IDTSInput100 input = destination.InputCollection[0];
IDTSVirtualInput100 vInput = input.GetVirtualInput();
// Iterate through the virtual input column collection.
foreach (IDTSVirtualInputColumn100 vColumn in vInput.VirtualInputColumnCollection)
{
// Call the SetUsageType method of the destination
// to add each available virtual input column as an input column.
destDesignTime.SetUsageType(
input.ID, vInput, vColumn.LineageID, DTSUsageType.UT_READONLY);
}
// Verify that the columns have been added to the input.
foreach (IDTSInputColumn100 inputColumn in destination.InputCollection[0].InputColumnCollection)
Console.WriteLine(inputColumn.Name);
Console.Read();
// Add other components to the data flow and connect them.
}
}
}
Imports Microsoft.SqlServer.Dts.Runtime
Imports Microsoft.SqlServer.Dts.Pipeline
Imports Microsoft.SqlServer.Dts.Pipeline.Wrapper
Module Module1
Sub Main()
' Create a package and add a Data Flow task.
Dim package As Microsoft.SqlServer.Dts.Runtime.Package = _
New Microsoft.SqlServer.Dts.Runtime.Package()
Dim e As Executable = package.Executables.Add("STOCK:PipelineTask")
Dim thMainPipe As Microsoft.SqlServer.Dts.Runtime.TaskHost = _
CType(e, Microsoft.SqlServer.Dts.Runtime.TaskHost)
Dim dataFlowTask As MainPipe = CType(thMainPipe.InnerObject, MainPipe)
' Add an OLE DB connection manager to the package.
Dim conMgr As ConnectionManager = package.Connections.Add("OLEDB")
conMgr.ConnectionString = "Provider=SQLOLEDB.1;" & _
"Data Source=<servername>;Initial Catalog=AdventureWorks;" & _
"Integrated Security=SSPI;"
conMgr.Name = "SSIS Connection Manager for OLE DB"
conMgr.Description = "OLE DB connection to the AdventureWorks database."
' Create and configure an OLE DB source component.
Dim source As IDTSComponentMetaData100 = _
dataFlowTask.ComponentMetaDataCollection.New
source.ComponentClassID = "DTSAdapter.OleDbSource"
' Create the design-time instance of the source.
Dim srcDesignTime As CManagedComponentWrapper = source.Instantiate
' The ProvideComponentProperties method creates a default output.
srcDesignTime.ProvideComponentProperties()
' Assign the connection manager.
source.RuntimeConnectionCollection(0).ConnectionManager = _
DtsConvert.GetExtendedInterface(conMgr)
' Set the custom properties of the source.
srcDesignTime.SetComponentProperty("AccessMode", 2)
srcDesignTime.SetComponentProperty("SqlCommand", _
"Select * from Production.Product")
' Connect to the data source,
' and then update the metadata for the source.
srcDesignTime.AcquireConnections(Nothing)
srcDesignTime.ReinitializeMetaData()
srcDesignTime.ReleaseConnections()
' Create and configure an OLE DB destination.
Dim destination As IDTSComponentMetaData100 = _
dataFlowTask.ComponentMetaDataCollection.New
destination.ComponentClassID = "DTSAdapter.OleDbDestination"
' Create the design-time instance of the destination.
Dim destDesignTime As CManagedComponentWrapper = destination.Instantiate
' The ProvideComponentProperties method creates a default input.
destDesignTime.ProvideComponentProperties()
' Create the path from source to destination.
Dim path As IDTSPath100 = dataFlowTask.PathCollection.New
path.AttachPathAndPropagateNotifications(source.OutputCollection(0), _
destination.InputCollection(0))
' Get the destination's default input and virtual input.
Dim input As IDTSInput100 = destination.InputCollection(0)
Dim vInput As IDTSVirtualInput100 = input.GetVirtualInput
' Iterate through the virtual input column collection.
For Each vColumn As IDTSVirtualInputColumn100 In vInput.VirtualInputColumnCollection
' Call the SetUsageType method of the destination
' to add each available virtual input column as an input column.
destDesignTime.SetUsageType(input.ID, vInput, vColumn.LineageID, DTSUsageType.UT_READONLY)
Next
' Verify that the columns have been added to the input.
For Each inputColumn As IDTSInputColumn100 In destination.InputCollection(0).InputColumnCollection
Console.WriteLine(inputColumn.Name)
Next
Console.Read()
' Add other components to the data flow and connect them.
End Sub
End Module
|