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SqlBulkCopyColumnMappingCollection Class

Note: This class is new in the .NET Framework version 2.0.

Collection of SqlBulkCopyColumnMapping objects that inherits from CollectionBase.

Namespace: System.Data.SqlClient
Assembly: System.Data (in system.data.dll)

'Declaration
Public NotInheritable Class SqlBulkCopyColumnMappingCollection
	Inherits CollectionBase
'Usage
Dim instance As SqlBulkCopyColumnMappingCollection

public final class SqlBulkCopyColumnMappingCollection extends CollectionBase
public final class SqlBulkCopyColumnMappingCollection extends CollectionBase

Column mappings define the mapping between data source and the target table.

If mappings are not defined—that is, the ColumnMappings collection is empty—the columns are mapped implicitly based on ordinal position. For this to work, source and target schemas must match. If they do not, an InvalidOperationException is thrown.

If the ColumnMappings collection is not empty, not every column present in the data source has to be specified. Those not mapped by the collection are ignored.

You can refer to source and target columns by either name or ordinal. You can mix by-name and by-ordinal column references in the same mappings collection.

The following example bulk copies data from a source table in the AdventureWorks sample database to a destination table in the same database. Although the number of columns in the destination matches the number of columns in the source, the column names and ordinal positions do not match. SqlBulkCopyColumnMapping are added to the SqlBulkCopyColumnMappingCollection for the SqlBulkCopy object to create a column map for the bulk copy.

NoteImportant:

This sample will not run unless you have created the work tables as described in Creating Tables for the Bulk Copy Examples. This code is provided to demonstrate the syntax for using SqlBulkCopy only. If the source and destination tables are in the same SQL Server instance, it is easier and faster to use a Transact-SQL INSERT … SELECT statement to copy the data.

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"

                ' The column order in the source doesn't match the order 
                ' in the destination, so ColumnMappings must be defined.
                bulkCopy.ColumnMappings.Add("ProductID", "ProdID")
                bulkCopy.ColumnMappings.Add("Name", "ProdName")
                bulkCopy.ColumnMappings.Add("ProductNumber", "ProdNum")

                ' 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

System.Object
   System.Collections.CollectionBase
    System.Data.SqlClient.SqlBulkCopyColumnMappingCollection

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Windows 98, Windows 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.

.NET Framework

Supported in: 2.0

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