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SqlBulkCopy.WriteToServer Method (IDataReader)

Copies all rows in the supplied IDataReader to a destination table specified by the DestinationTableName property of the SqlBulkCopy object.

Namespace:  System.Data.SqlClient
Assembly:  System.Data (in System.Data.dll)

public void WriteToServer(
	IDataReader reader


Type: System.Data.IDataReader

A IDataReader whose rows will be copied to the destination table.

The copy operation starts at the next available row in the reader. Most of the time, the reader was just returned by ExecuteReader or a similar call, so the next available row is the first row. To process multiple results, call NextResult on the data reader and call WriteToServer again.

Note that using WriteToServer modifies the state of the reader. The method will call Read until it returns false, the operation is aborted, or an error occurs. This means that the data reader will be in a different state, probably at the end of the result set, when the WriteToServer operation is complete.

While the bulk copy operation is in progress, the associated destination SqlConnection is busy serving it, and no other operations can be performed on the connection.

The ColumnMappings collection maps from the data reader columns to the destination database table.

The following console application demonstrates how to bulk load data from a SqlDataReader. The destination table is a table in the AdventureWorks database.

Important noteImportant

This sample will not run unless you have created the work tables as described in Bulk Copy Example Setup. This code is provided to demonstrate the syntax for using SqlBulkCopy only. If the source and destination tables are in the same SQL Server instance, it is easier and faster to use a Transact-SQL INSERT … SELECT statement to copy the 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))

            // Perform an initial count on the destination table.
            SqlCommand commandRowCount = new SqlCommand(
                "SELECT COUNT(*) FROM " +
            long countStart = System.Convert.ToInt32(
            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 =

            // Set up the bulk copy object using a connection string.  
            // In the real world you would not use SqlBulkCopy to move 
            // data from one table to the other in the same database. 
            using (SqlBulkCopy bulkCopy =
                       new SqlBulkCopy(connectionString))
                bulkCopy.DestinationTableName =

                    // Write from the source to the destination.
                catch (Exception ex)
                    // Close the SqlDataReader. The SqlBulkCopy 
                    // object is automatically closed at the end 
                    // of the using block.

            // Perform a final count on the destination  
            // table to see how many rows were added. 
            long countEnd = System.Convert.ToInt32(
            Console.WriteLine("Ending row count = {0}", countEnd);
            Console.WriteLine("{0} rows were added.", countEnd - countStart);
            Console.WriteLine("Press Enter to finish.");

    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;";

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1
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