SqlBulkCopyColumnMapping Class
Defines the mapping between a column in a SqlBulkCopy instance's data source and a column in the instance's destination table.
Assembly: System.Data (in System.Data.dll)
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 will be 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 also 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, and each destination column is in the same ordinal position as its corresponding source column, the column names do not match. SqlBulkCopyColumnMapping objects are used to create a column map for the bulk copy.
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This sample will not run unless you have created the work tables as described in Bulk Copy Example Setup (ADO.NET). 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" ' Set up the column mappings by name. Dim mapID As New _ SqlBulkCopyColumnMapping("ProductID", "ProdID") bulkCopy.ColumnMappings.Add(mapID) Dim mapName As New _ SqlBulkCopyColumnMapping("Name", "ProdName") bulkCopy.ColumnMappings.Add(mapName) Dim mapMumber As New _ SqlBulkCopyColumnMapping("ProductNumber", "ProdNum") bulkCopy.ColumnMappings.Add(mapMumber) ' 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
Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98
The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
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