SqlBulkCopyColumnMapping.DestinationColumn Propiedad

Definición

Espacio de nombres:

System.Data.SqlClient

Ensamblado:

System.Data.dll

Nombre de la columna que se está asignando en la tabla de la base de datos de destino.

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

public string DestinationColumn { get; set; }

member this.DestinationColumn : string with get, set

Public Property DestinationColumn As String

Valor de propiedad

String

El valor de cadena de la propiedad DestinationColumn.

Ejemplos

En el ejemplo siguiente se copian de forma masiva datos de una tabla de origen en la base de datos de ejemplo AdventureWorks a una tabla de destino en la misma base de datos. Aunque el número de columnas del destino coincide con el número de columnas del origen, los nombres de columna y las posiciones ordinales no coinciden. SqlBulkCopyColumnMapping Los objetos se usan para crear un mapa de columnas para la copia masiva.

Importante

Este ejemplo no se ejecuta a menos que haya creado las tablas de trabajo como se describe en Configuración de ejemplos de copia masiva. Este código se proporciona para mostrar la sintaxis para usar SqlBulkCopy. Si las tablas de origen y destino están en la misma instancia de SQL Server, es más fácil y rápido usar una instrucción Transact-SQL INSERT … SELECT para copiar los datos.

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

Comentarios

Las DestinationColumn propiedades y DestinationOrdinal son mutuamente excluyentes. El último conjunto de valores tiene prioridad.

Consulte también

• Operaciones de copia masiva en SQL Server
• Información general de ADO.NET