SqlBulkCopyColumnMapping.SourceColumn Eigenschaft

Definition

Namespace:

System.Data.SqlClient

Assembly:

System.Data.dll

Der Name der Spalte, die in der Datenquelle zugeordnet wird.

public:
 property System::String ^ SourceColumn { System::String ^ get(); void set(System::String ^ value); };

public string SourceColumn { get; set; }

member this.SourceColumn : string with get, set

Public Property SourceColumn As String

Eigenschaftswert

String

Der Zeichenfolgenwert der SourceColumn-Eigenschaft.

Beispiele

Im folgenden Beispiel werden Daten aus einer Quelltabelle in der Beispieldatenbank AdventureWorks in eine Zieltabelle derselben Datenbank massenkopiert. Obwohl die Anzahl der Spalten im Ziel mit der Anzahl der Spalten in der Quelle übereinstimmt, stimmen die Spaltennamen und Ordnungspositionen nicht überein. SqlBulkCopyColumnMapping -Objekte werden verwendet, um eine Spaltenzuordnung für den Massenkopiervorgang zu erstellen.

Wichtig

Dieses Beispiel wird nur ausgeführt, wenn Sie die Arbeitstabellen zuvor wie unter Massenkopierbeispiel-Einrichtung beschrieben erstellt haben. Der angegebene Code dient nur zur Demonstration der Syntax für die Verwendung von SqlBulkCopy. Wenn sich quell- und zieltabellen im gleichen SQL Server instance befinden, ist es einfacher und schneller, eine Transact-SQL-Anweisung INSERT … SELECT zum Kopieren der Daten zu verwenden.

using System.Data.SqlClient;

class Program
{
    static void Main()
    {
        string connectionString = GetConnectionString();
        // Open a sourceConnection to the AdventureWorks database.
        using (SqlConnection sourceConnection =
                   new SqlConnection(connectionString))
        {
            sourceConnection.Open();

            // Perform an initial count on the destination table.
            SqlCommand commandRowCount = new SqlCommand(
                "SELECT COUNT(*) FROM " +
                "dbo.BulkCopyDemoDifferentColumns;",
                sourceConnection);
            long countStart = System.Convert.ToInt32(
                commandRowCount.ExecuteScalar());
            Console.WriteLine("Starting row count = {0}", countStart);

            // Get data from the source table as a SqlDataReader.
            SqlCommand commandSourceData = new SqlCommand(
                "SELECT ProductID, Name, " +
                "ProductNumber " +
                "FROM Production.Product;", sourceConnection);
            SqlDataReader reader =
                commandSourceData.ExecuteReader();

            // Set up the bulk copy object.
            using (SqlBulkCopy bulkCopy =
                       new SqlBulkCopy(connectionString))
            {
                bulkCopy.DestinationTableName =
                    "dbo.BulkCopyDemoDifferentColumns";

                // Set up the column mappings source and destination.
                SqlBulkCopyColumnMapping mapID = new SqlBulkCopyColumnMapping();
                mapID.SourceColumn = "ProductID";
                mapID.DestinationColumn = "ProdID";
                bulkCopy.ColumnMappings.Add(mapID);

                SqlBulkCopyColumnMapping mapName = new SqlBulkCopyColumnMapping();
                mapName.SourceColumn = "Name";
                mapName.DestinationColumn = "ProdName";
                bulkCopy.ColumnMappings.Add(mapName);

                SqlBulkCopyColumnMapping mapNumber = new SqlBulkCopyColumnMapping();
                mapNumber.SourceColumn = "ProductNumber";
                mapNumber.DestinationColumn = "ProdNum";
                bulkCopy.ColumnMappings.Add(mapNumber);

                // Write from the source to the destination.
                try
                {
                    bulkCopy.WriteToServer(reader);
                }
                catch (Exception ex)
                {
                    Console.WriteLine(ex.Message);
                }
                finally
                {
                    // Close the SqlDataReader. The SqlBulkCopy
                    // object is automatically closed at the end
                    // of the using block.
                    reader.Close();
                }
            }

            // Perform a final count on the destination
            // table to see how many rows were added.
            long countEnd = System.Convert.ToInt32(
                commandRowCount.ExecuteScalar());
            Console.WriteLine("Ending row count = {0}", countEnd);
            Console.WriteLine("{0} rows were added.", countEnd - countStart);
            Console.WriteLine("Press Enter to finish.");
            Console.ReadLine();
        }
    }

    private static string GetConnectionString()
        // To avoid storing the sourceConnection string in your code,
        // you can retrieve it from a configuration file.
    {
        return "Data Source=(local); " +
            " Integrated Security=true;" +
            "Initial Catalog=AdventureWorks;";
    }
}

Imports System.Data.SqlClient

Module Module1
    Sub Main()
        Dim connectionString As String = GetConnectionString()

        ' Open a connection to the AdventureWorks database.
        Using sourceConnection As SqlConnection = _
           New SqlConnection(connectionString)
            sourceConnection.Open()

            ' Perform an initial count on the destination table.
            Dim commandRowCount As New SqlCommand( _
            "SELECT COUNT(*) FROM dbo.BulkCopyDemoDifferentColumns;", _
                sourceConnection)
            Dim countStart As Long = _
               System.Convert.ToInt32(commandRowCount.ExecuteScalar())
            Console.WriteLine("Starting row count = {0}", countStart)

            ' Get data from the source table as a SqlDataReader.
            Dim commandSourceData As SqlCommand = New SqlCommand( _
               "SELECT ProductID, Name, ProductNumber " & _
               "FROM Production.Product;", sourceConnection)
            Dim reader As SqlDataReader = commandSourceData.ExecuteReader

            ' Set up the bulk copy object.
            Using bulkCopy As SqlBulkCopy = New SqlBulkCopy(connectionString)
                bulkCopy.DestinationTableName = _
                "dbo.BulkCopyDemoDifferentColumns"

                ' Set up the column mappings source and destination.
                Dim mapID As New SqlBulkCopyColumnMapping()
                mapID.SourceColumn = "ProductID"
                mapID.DestinationColumn = "ProdID"
                bulkCopy.ColumnMappings.Add(mapID)

                Dim mapName As New SqlBulkCopyColumnMapping()
                mapName.SourceColumn = "Name"
                mapName.DestinationColumn = "ProdName"
                bulkCopy.ColumnMappings.Add(mapName)

                Dim mapNumber As New SqlBulkCopyColumnMapping()
                mapNumber.SourceColumn = "ProductNumber"
                mapNumber.DestinationColumn = "ProdNum"
                bulkCopy.ColumnMappings.Add(mapNumber)

                ' Write from the source to the destination.
                Try
                    bulkCopy.WriteToServer(reader)

                Catch ex As Exception
                    Console.WriteLine(ex.Message)

                Finally
                    ' Close the SqlDataReader. The SqlBulkCopy
                    ' object is automatically closed at the end
                    ' of the Using block.
                    reader.Close()
                End Try
            End Using

            ' Perform a final count on the destination table
            ' to see how many rows were added.
            Dim countEnd As Long = _
                System.Convert.ToInt32(commandRowCount.ExecuteScalar())
            Console.WriteLine("Ending row count = {0}", countEnd)
            Console.WriteLine("{0} rows were added.", countEnd - countStart)

            Console.WriteLine("Press Enter to finish.")
            Console.ReadLine()
        End Using
    End Sub

    Private Function GetConnectionString() As String
        ' To avoid storing the sourceConnection string in your code, 
        ' you can retrieve it from a configuration file. 
        Return "Data Source=(local);" & _
            "Integrated Security=true;" & _
            "Initial Catalog=AdventureWorks;"
    End Function
End Module

Hinweise

Die SourceColumn Eigenschaften und SourceOrdinal schließen sich gegenseitig aus. Der letzte Wertsatz hat Vorrang.

Weitere Informationen

• Massenkopiervorgänge in SQL Server
• Übersicht über ADO.NET