SqlBulkCopyColumnMapping.DestinationOrdinal Egenskap
Definition
Viktigt
En del information gäller för förhandsversionen av en produkt och kan komma att ändras avsevärt innan produkten blir allmänt tillgänglig. Microsoft lämnar inga garantier, uttryckliga eller underförstådda, avseende informationen som visas här.
Ordningstalet för målkolumnen i måltabellen.
public:
property int DestinationOrdinal { int get(); void set(int value); };
public int DestinationOrdinal { get; set; }
member this.DestinationOrdinal : int with get, set
Public Property DestinationOrdinal As Integer
Egenskapsvärde
Heltalsvärdet för DestinationOrdinal egenskapen eller -1 om egenskapen inte har angetts.
Exempel
I följande exempel kopieras data från en källtabell i AdventureWorks-exempeldatabasen till en måltabell i samma databas. Även om antalet kolumner i målet matchar antalet kolumner i källan matchar inte kolumnnamnen och ordningspositionerna. SqlBulkCopyColumnMapping objekt används för att skapa en kolumnkarta för masskopian.
Important
Det här exemplet körs inte om du inte har skapat arbetstabellerna enligt beskrivningen i Inställning för masskopieringsexempel. Den här koden tillhandahålls för att demonstrera syntaxen för att endast använda SqlBulkCopy . Om käll- och måltabellerna finns i samma SQL Server instans är det enklare och snabbare att använda en Transact-SQL INSERT … SELECT-instruktion för att kopiera data.
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.SourceOrdinal = 0;
mapID.DestinationOrdinal = 0;
bulkCopy.ColumnMappings.Add(mapID);
SqlBulkCopyColumnMapping mapName = new SqlBulkCopyColumnMapping();
mapName.SourceOrdinal = 1;
mapName.DestinationOrdinal = 2;
bulkCopy.ColumnMappings.Add(mapName);
SqlBulkCopyColumnMapping mapNumber = new SqlBulkCopyColumnMapping();
mapNumber.SourceOrdinal = 2;
mapNumber.DestinationOrdinal = 1;
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.SourceOrdinal = 0
mapID.DestinationOrdinal = 0
bulkCopy.ColumnMappings.Add(mapID)
Dim mapName As New SqlBulkCopyColumnMapping()
mapName.SourceOrdinal = 1
mapName.DestinationOrdinal = 2
bulkCopy.ColumnMappings.Add(mapName)
Dim mapNumber As New SqlBulkCopyColumnMapping()
mapNumber.SourceOrdinal = 2
mapNumber.DestinationOrdinal = 1
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
Kommentarer
Egenskaperna DestinationColumn och DestinationOrdinal är ömsesidigt uteslutande. Den sista värdeuppsättningen har företräde.