SqlBulkCopyColumnMappingCollection Třída

Definice

public ref class SqlBulkCopyColumnMappingCollection sealed : System::Collections::IList

public ref class SqlBulkCopyColumnMappingCollection sealed : System::Collections::CollectionBase

public sealed class SqlBulkCopyColumnMappingCollection : System.Collections.IList

public sealed class SqlBulkCopyColumnMappingCollection : System.Collections.CollectionBase

type SqlBulkCopyColumnMappingCollection = class
    interface ICollection
    interface IEnumerable
    interface IList

type SqlBulkCopyColumnMappingCollection = class
    inherit CollectionBase

Public NotInheritable Class SqlBulkCopyColumnMappingCollection
Implements IList

Public NotInheritable Class SqlBulkCopyColumnMappingCollection
Inherits CollectionBase

Dědičnost

Object

SqlBulkCopyColumnMappingCollection

Dědičnost

Object

CollectionBase

SqlBulkCopyColumnMappingCollection

Implementuje

ICollection IEnumerable IList

Příklady

Následující příklad hromadně zkopíruje data ze zdrojové tabulky v ukázkové databázi AdventureWorks do cílové tabulky ve stejné databázi. I když počet sloupců v cíli odpovídá počtu sloupců ve zdroji, názvy sloupců a pořadí řad se neshodují. SqlBulkCopyColumnMapping jsou přidány SqlBulkCopyColumnMappingCollection do objektu SqlBulkCopy pro vytvoření mapování sloupců pro hromadnou kopii.

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";

                // 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 (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"

                ' 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

Poznámky

Mapování sloupců definují mapování mezi zdrojem dat a cílovou tabulkou.

Pokud mapování nejsou definovaná – to znamená, ColumnMappings že kolekce je prázdná – sloupce se mapují implicitně na základě řadové pozice. Aby to fungovalo, musí se zdrojová a cílová schémata shodovat. Pokud ne, InvalidOperationException je vyhozen.

ColumnMappings Pokud kolekce není prázdná, není nutné zadat každý sloupec, který je ve zdroji dat. Ty, které kolekce nemapuje, se ignorují.

Na zdrojový a cílový sloupec můžete odkazovat podle názvu nebo pořadové řady. Ve stejné kolekci mapování můžete kombinovat odkazy na sloupce podle názvu a podle řad.

Vlastnosti

Metody

Explicitní implementace rozhraní

Metody rozšíření

Platí pro

Viz také

• Operace hromadného kopírování na SQL Serveru
• Přehled ADO.NET