SqlBulkCopyColumnMapping.SourceOrdinal 屬性
定義
重要
部分資訊涉及發行前產品,在發行之前可能會有大幅修改。 Microsoft 對此處提供的資訊,不做任何明確或隱含的瑕疵擔保。
資料來源內來源資料行的序數位置。
public:
property int SourceOrdinal { int get(); void set(int value); };
public int SourceOrdinal { get; set; }
member this.SourceOrdinal : int with get, set
Public Property SourceOrdinal As Integer
屬性值
SourceOrdinal 屬性的整數值。
範例
下列範例會從 AdventureWorks 範例資料庫中的來源資料表,將資料大量複製到相同資料庫中的目的地資料表。 雖然目的地中的資料行數目符合來源中的資料行數目,但是資料行名稱和序數位置不相符。 SqlBulkCopyColumnMapping 物件可用來建立大量複製的資料行對應。
重要
除非您已建立如 大量複製範例安裝程式中所述的工作資料表,否則不會執行此範例。
這個程式碼僅是為了示範使用 SqlBulkCopy 的語法而提供。 如果來源和目的地資料表位於相同的SQL Server實例中,使用 Transact-SQL INSERT … SELECT
語句來複製資料會比較簡單且更快速。
using Microsoft.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;";
}
}
備註
SourceColumn和 SourceOrdinal 屬性互斥。 最後一個值集優先。