Connecting to Data Sources in the Script Component

Articolo
12/15/2008

A connection manager is a convenient unit that encapsulates and stores the information that is required to connect to a data source of a particular type. For more information, see Connessioni in Integration Services and Gestioni connessioni.

You can make existing connection managers available for access by the custom script in the source or destination component by clicking the Add and Remove buttons on the Connection Managers page of the Script Transformation Editor. However, you must write your own custom code to load or save your data, and possibly to open and close the connection to the data source. For more information about the Connection Managers page of the Script Transformation Editor, see Configuring the Script Component in the Script Component Editor and Editor trasformazione Script (pagina Gestioni connessioni).

The Script component creates a Connections collection class in the ComponentWrapper project item that contains a strongly-typed accessor for each connection manager that has the same name as the connection manager itself. This collection is exposed through the Connections property of the ScriptMain class. The accessor property returns a reference to the connection manager as an instance of IDTSConnectionManager90. For example, if you have added a connection manager named MyADONETConnection on the Connection Managers page of the dialog box, you can obtain a reference to it in your script by adding the following code:

Dim myADONETConnectionManager As IDTSConnectionManager90 = _

Me.Connections.MyADONETConnection

[!NOTA] You must know the type of connection that is returned by the connection manager before you call AcquireConnection. Because the Script task has Option Strict enabled, you must cast the connection, which is returned as type Object, to the appropriate connection type before you can use it.

Next, you call the AcquireConnection method of the specific connection manager to obtain either the underlying connection or the information that is required to connect to the data source. For example, you obtain a reference to the System.Data.SqlConnection wrapped by an ADO.NET connection manager by using the following code:

Dim myADOConnection As SqlConnection = _

CType(MyADONETConnectionManager.AcquireConnection(Nothing), SqlConnection)

In contrast, the same call to a flat file connection manager returns only the path and file name of the file data source.

Dim myFlatFile As String = _

CType(MyFlatFileConnectionManager.AcquireConnection(Nothing), String)

You then must provide this path and file name to a System.IO.StreamReader or Streamwriter to read or write the data in the flat file.

Importante:
When you write managed code in a Script component, you cannot call the AcquireConnection method of connection managers that return unmanaged objects, such as the OLE DB connection manager and the Excel connection manager. However, you can read the ConnectionString property of these connection managers, and connect to the data source directly in your code by using the connection string of an OLEDB connection from the System.Data.OleDb namespace. If you need to call the AcquireConnection method of a connection manager that returns an unmanaged object, use an ADO.NET connection manager. When you configure the ADO.NET connection manager to use an OLE DB provider, it connects by using the .NET Framework Data Provider for OLE DB. In this case, the AcquireConnection method returns a System.Data.OleDb.OleDbConnection instead of an unmanaged object. To configure an ADO.NET connection manager for use with an Excel data source, select the Microsoft OLE DB Provider for Jet, specify an Excel workbook, and then enter `Excel 8.0` (for Excel 97 and later) as the value of Extended Properties on the All page of the Connection Manager dialog box.

Importante:

When you write managed code in a Script component, you cannot call the AcquireConnection method of connection managers that return unmanaged objects, such as the OLE DB connection manager and the Excel connection manager. However, you can read the ConnectionString property of these connection managers, and connect to the data source directly in your code by using the connection string of an OLEDB connection from the System.Data.OleDb namespace. If you need to call the AcquireConnection method of a connection manager that returns an unmanaged object, use an ADO.NET connection manager. When you configure the ADO.NET connection manager to use an OLE DB provider, it connects by using the .NET Framework Data Provider for OLE DB. In this case, the AcquireConnection method returns a System.Data.OleDb.OleDbConnection instead of an unmanaged object. To configure an ADO.NET connection manager for use with an Excel data source, select the Microsoft OLE DB Provider for Jet, specify an Excel workbook, and then enter Excel 8.0 (for Excel 97 and later) as the value of Extended Properties on the All page of the Connection Manager dialog box.

For more information about how to use connection managers with the script component, see Creating a Source with the Script Component and Creating a Destination with the Script Component.

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Connecting to Data Sources in the Script Component

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