SqlBulkCopyColumnMapping.DestinationOrdinal 属性

定义

命名空间:

Microsoft.Data.SqlClient

程序集:

Microsoft.Data.SqlClient.dll

包:

Microsoft.Data.SqlClient v5.2.0

目标表中目标列的序号值。

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

属性值

Int32

DestinationOrdinal 属性的整数值，或者如果尚未设置该属性，则为 -1。

示例

以下示例将数据从“AdventureWorks”示例数据库中的源表大容量复制到同一个数据库中的目标表。 尽管目标中的列数与源中的列数匹配，但列名称和序号位置不匹配。 SqlBulkCopyColumnMapping 对象用于为大容量复制创建列映射。

重要

除非已按批量复制示例设置中所述创建了工作表，否则此示例不会运行。 提供此代码是为了演示仅使用 SqlBulkCopy 时的语法。 如果源表和目标表位于同一SQL Server实例中，则使用 Transact-SQL INSERT … SELECT 语句复制数据会更轻松、更快。

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;";
    }
}

注解

和 DestinationColumnDestinationOrdinal 属性互斥。 最后一个设置的值优先。