Mehrere Massenkopiervorgänge
Mithilfe einer einzelnen Instanz einer SqlBulkCopy-Klasse können Sie mehrere Massenkopiervorgänge ausführen. Wenn sich die Parameter für den Vorgang zwischen den Ausführungen ändern (z. B. der Name der Zieltabelle), müssen Sie sie vor allen nachfolgenden Aufrufen einer der WriteToServer-Methoden ändern, wie im folgenden Beispiel gezeigt. Sofern sie nicht explizit geändert werden, bleiben alle Eigenschaftswerte die gleichen wie beim letzten Massenkopiervorgang für eine bestimmte Instanz.
Hinweis
Das Ausführen mehrerer Massenkopiervorgänge mithilfe der gleichen Instanz von SqlBulkCopy ist normalerweise effizienter als die Verwendung einer separaten Instanz für jeden Vorgang.
Wenn Sie mehrere Massenkopiervorgänge mithilfe des gleichen SqlBulkCopy-Objekts ausführen, bestehen normalerweise keine Einschränkungen hinsichtlich der Gleichheit oder Verschiedenheit der Quell- und Zielinformationen für die einzelnen Vorgänge. Sie müssen jedoch sicherstellen, dass die Informationen zur Spaltenzuordnung bei jedem Schreibvorgang auf dem Server ordnungsgemäß festgelegt sind.
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 die Quell- und Zieltabellen in der gleichen SQL Server-Instanz befinden, ist die Verwendung einer Transact-SQL-Anweisung INSERT … SELECT zum Kopieren der Daten einfacher und schneller.
static void Main()
{
var connectionString = GetConnectionString();
// Open a connection to the AdventureWorks database.
using (SqlConnection connection =
new(connectionString))
{
connection.Open();
// Empty the destination tables.
SqlCommand deleteHeader = new(
"DELETE FROM dbo.BulkCopyDemoOrderHeader;",
connection);
deleteHeader.ExecuteNonQuery();
SqlCommand deleteDetail = new(
"DELETE FROM dbo.BulkCopyDemoOrderDetail;",
connection);
deleteDetail.ExecuteNonQuery();
// Perform an initial count on the destination
// table with matching columns.
SqlCommand countRowHeader = new(
"SELECT COUNT(*) FROM dbo.BulkCopyDemoOrderHeader;",
connection);
long countStartHeader = Convert.ToInt32(
countRowHeader.ExecuteScalar());
Console.WriteLine(
"Starting row count for Header table = {0}",
countStartHeader);
// Perform an initial count on the destination
// table with different column positions.
SqlCommand countRowDetail = new(
"SELECT COUNT(*) FROM dbo.BulkCopyDemoOrderDetail;",
connection);
long countStartDetail = Convert.ToInt32(
countRowDetail.ExecuteScalar());
Console.WriteLine(
"Starting row count for Detail table = {0}",
countStartDetail);
// Get data from the source table as a SqlDataReader.
// The Sales.SalesOrderHeader and Sales.SalesOrderDetail
// tables are quite large and could easily cause a timeout
// if all data from the tables is added to the destination.
// To keep the example simple and quick, a parameter is
// used to select only orders for a particular account
// as the source for the bulk insert.
SqlCommand headerData = new(
"SELECT [SalesOrderID], [OrderDate], " +
"[AccountNumber] FROM [Sales].[SalesOrderHeader] " +
"WHERE [AccountNumber] = @accountNumber;",
connection);
SqlParameter parameterAccount = new()
{
ParameterName = "@accountNumber",
SqlDbType = SqlDbType.NVarChar,
Direction = ParameterDirection.Input,
Value = "10-4020-000034"
};
headerData.Parameters.Add(parameterAccount);
SqlDataReader readerHeader = headerData.ExecuteReader();
// Get the Detail data in a separate connection.
using (SqlConnection connection2 = new(connectionString))
{
connection2.Open();
SqlCommand sourceDetailData = new(
"SELECT [Sales].[SalesOrderDetail].[SalesOrderID], [SalesOrderDetailID], " +
"[OrderQty], [ProductID], [UnitPrice] FROM [Sales].[SalesOrderDetail] " +
"INNER JOIN [Sales].[SalesOrderHeader] ON [Sales].[SalesOrderDetail]." +
"[SalesOrderID] = [Sales].[SalesOrderHeader].[SalesOrderID] " +
"WHERE [AccountNumber] = @accountNumber;", connection2);
SqlParameter accountDetail = new()
{
ParameterName = "@accountNumber",
SqlDbType = SqlDbType.NVarChar,
Direction = ParameterDirection.Input,
Value = "10-4020-000034"
};
sourceDetailData.Parameters.Add(accountDetail);
SqlDataReader readerDetail = sourceDetailData.ExecuteReader();
// Create the SqlBulkCopy object.
using (SqlBulkCopy bulkCopy =
new(connectionString))
{
bulkCopy.DestinationTableName =
"dbo.BulkCopyDemoOrderHeader";
// Guarantee that columns are mapped correctly by
// defining the column mappings for the order.
bulkCopy.ColumnMappings.Add("SalesOrderID", "SalesOrderID");
bulkCopy.ColumnMappings.Add("OrderDate", "OrderDate");
bulkCopy.ColumnMappings.Add("AccountNumber", "AccountNumber");
// Write readerHeader to the destination.
try
{
bulkCopy.WriteToServer(readerHeader);
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
finally
{
readerHeader.Close();
}
// Set up the order details destination.
bulkCopy.DestinationTableName = "dbo.BulkCopyDemoOrderDetail";
// Clear the ColumnMappingCollection.
bulkCopy.ColumnMappings.Clear();
// Add order detail column mappings.
bulkCopy.ColumnMappings.Add("SalesOrderID", "SalesOrderID");
bulkCopy.ColumnMappings.Add("SalesOrderDetailID", "SalesOrderDetailID");
bulkCopy.ColumnMappings.Add("OrderQty", "OrderQty");
bulkCopy.ColumnMappings.Add("ProductID", "ProductID");
bulkCopy.ColumnMappings.Add("UnitPrice", "UnitPrice");
// Write readerDetail to the destination.
try
{
bulkCopy.WriteToServer(readerDetail);
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
finally
{
readerDetail.Close();
}
}
// Perform a final count on the destination
// tables to see how many rows were added.
long countEndHeader = Convert.ToInt32(
countRowHeader.ExecuteScalar());
Console.WriteLine("{0} rows were added to the Header table.",
countEndHeader - countStartHeader);
long countEndDetail = Convert.ToInt32(
countRowDetail.ExecuteScalar());
Console.WriteLine("{0} rows were added to the Detail table.",
countEndDetail - countStartDetail);
Console.WriteLine("Press Enter to finish.");
Console.ReadLine();
}
}
}
Imports System.Data.SqlClient
Module Module1
Sub Main()
Dim connectionString As String = GetConnectionString()
' Open a connection to the AdventureWorks database.
Using connection As SqlConnection = New SqlConnection(connectionString)
connection.Open()
' Empty the destination tables.
Dim deleteHeader As New SqlCommand( _
"DELETE FROM dbo.BulkCopyDemoOrderHeader;", connection)
deleteHeader.ExecuteNonQuery()
deleteHeader.Dispose()
Dim deleteDetail As New SqlCommand( _
"DELETE FROM dbo.BulkCopyDemoOrderDetail;", connection)
deleteDetail.ExecuteNonQuery()
' Perform an initial count on the destination table
' with matching columns.
Dim countRowHeader As New SqlCommand( _
"SELECT COUNT(*) FROM dbo.BulkCopyDemoOrderHeader;", _
connection)
Dim countStartHeader As Long = System.Convert.ToInt32( _
countRowHeader.ExecuteScalar())
Console.WriteLine("Starting row count for Header table = {0}", _
countStartHeader)
' Perform an initial count on the destination table
' with different column positions.
Dim countRowDetail As New SqlCommand( _
"SELECT COUNT(*) FROM dbo.BulkCopyDemoOrderDetail;", _
connection)
Dim countStartDetail As Long = System.Convert.ToInt32( _
countRowDetail.ExecuteScalar())
Console.WriteLine("Starting row count for Detail table = " & _
countStartDetail)
' Get data from the source table as a SqlDataReader.
' The Sales.SalesOrderHeader and Sales.SalesOrderDetail
' tables are quite large and could easily cause a timeout
' if all data from the tables is added to the destination.
' To keep the example simple and quick, a parameter is
' used to select only orders for a particular account as
' the source for the bulk insert.
Dim headerData As SqlCommand = New SqlCommand( _
"SELECT [SalesOrderID], [OrderDate], " & _
"[AccountNumber] FROM [Sales].[SalesOrderHeader] " & _
"WHERE [AccountNumber] = @accountNumber;", _
connection)
Dim parameterAccount As SqlParameter = New SqlParameter()
parameterAccount.ParameterName = "@accountNumber"
parameterAccount.SqlDbType = SqlDbType.NVarChar
parameterAccount.Direction = ParameterDirection.Input
parameterAccount.Value = "10-4020-000034"
headerData.Parameters.Add(parameterAccount)
Dim readerHeader As SqlDataReader = _
headerData.ExecuteReader()
' Get the Detail data in a separate connection.
Using connection2 As SqlConnection = New SqlConnection(connectionString)
connection2.Open()
Dim sourceDetailData As SqlCommand = New SqlCommand( _
"SELECT [Sales].[SalesOrderDetail].[SalesOrderID], " & _
"[SalesOrderDetailID], [OrderQty], [ProductID], [UnitPrice] " & _
"FROM [Sales].[SalesOrderDetail] INNER JOIN " & _
"[Sales].[SalesOrderHeader] " & _
"ON [Sales].[SalesOrderDetail].[SalesOrderID] = " & _
"[Sales].[SalesOrderHeader].[SalesOrderID] " & _
"WHERE [AccountNumber] = @accountNumber;", connection2)
Dim accountDetail As SqlParameter = New SqlParameter()
accountDetail.ParameterName = "@accountNumber"
accountDetail.SqlDbType = SqlDbType.NVarChar
accountDetail.Direction = ParameterDirection.Input
accountDetail.Value = "10-4020-000034"
sourceDetailData.Parameters.Add( _
accountDetail)
Dim readerDetail As SqlDataReader = _
sourceDetailData.ExecuteReader()
' Create the SqlBulkCopy object.
Using bulkCopy As SqlBulkCopy = _
New SqlBulkCopy(connectionString)
bulkCopy.DestinationTableName = "dbo.BulkCopyDemoOrderHeader"
' Guarantee that columns are mapped correctly by
' defining the column mappings for the order.
bulkCopy.ColumnMappings.Add("SalesOrderID", "SalesOrderID")
bulkCopy.ColumnMappings.Add("OrderDate", "OrderDate")
bulkCopy.ColumnMappings.Add("AccountNumber", "AccountNumber")
' Write readerHeader to the destination.
Try
bulkCopy.WriteToServer(readerHeader)
Catch ex As Exception
Console.WriteLine(ex.Message)
Finally
readerHeader.Close()
End Try
' Set up the order details destination.
bulkCopy.DestinationTableName = "dbo.BulkCopyDemoOrderDetail"
' Clear the ColumnMappingCollection.
bulkCopy.ColumnMappings.Clear()
' Add order detail column mappings.
bulkCopy.ColumnMappings.Add("SalesOrderID", "SalesOrderID")
bulkCopy.ColumnMappings.Add("SalesOrderDetailID", "SalesOrderDetailID")
bulkCopy.ColumnMappings.Add("OrderQty", "OrderQty")
bulkCopy.ColumnMappings.Add("ProductID", "ProductID")
bulkCopy.ColumnMappings.Add("UnitPrice", "UnitPrice")
' Write readerDetail to the destination.
Try
bulkCopy.WriteToServer(readerDetail)
Catch ex As Exception
Console.WriteLine(ex.Message)
Finally
readerDetail.Close()
End Try
End Using
' Perform a final count on the destination tables
' to see how many rows were added.
Dim countEndHeader As Long = System.Convert.ToInt32( _
countRowHeader.ExecuteScalar())
Console.WriteLine("{0} rows were added to the Header table.", _
countEndHeader - countStartHeader)
Dim countEndDetail As Long = System.Convert.ToInt32( _
countRowDetail.ExecuteScalar())
Console.WriteLine("{0} rows were added to the Detail table.", _
countEndDetail - countStartDetail)
Console.WriteLine("Press Enter to finish.")
Console.ReadLine()
End Using
End Using
End Sub
Private Function GetConnectionString() As String
Throw New NotImplementedException()
End Function
End Module