Single bulk copy operations
The simplest approach to performing a SQL Server bulk copy operation is to perform a single operation against a database. By default, a bulk copy operation is performed as an isolated operation: the copy operation occurs in a non-transacted way, with no opportunity for rolling it back.
Note
If you need to roll back all or part of the bulk copy when an error occurs, you can either use a SqlBulkCopy-managed transaction, or perform the bulk copy operation within an existing transaction. SqlBulkCopy will also work with System.Transactions if the connection is enlisted (implicitly or explicitly) into a System.Transactions transaction.
For more information, see Transaction and Bulk Copy Operations.
The general steps for performing a bulk copy operation are as follows:
Connect to the source server and obtain the data to be copied. Data can also come from other sources, if it can be retrieved from an IDataReader or DataTable object.
Connect to the destination server (unless you want SqlBulkCopy to establish a connection for you).
Create a SqlBulkCopy object, setting any necessary properties.
Set the DestinationTableName property to indicate the target table for the bulk insert operation.
Call one of the WriteToServer methods.
Optionally, update properties and call WriteToServer again as necessary.
Call Close, or wrap the bulk copy operations within a
Usingstatement.
Caution
We recommend that the source and target column data types match. If the data types do not match, SqlBulkCopy attempts to convert each source value to the target data type, using the rules employed by Value. Conversions can affect performance, and also can result in unexpected errors. For example, a Double data type can be converted to a Decimal data type most of the time, but not always.
Example
The following console application demonstrates how to load data using the SqlBulkCopy class. In this example, a SqlDataReader is used to copy data from the Production.Product table in the SQL Server AdventureWorks database to a similar table in the same database.
Important
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 located in the same SQL Server instance, it is easier and faster to use a Transact-SQL INSERT … SELECT statement to copy the data.
static void Main()
{
var connectionString = GetConnectionString();
// Open a sourceConnection to the AdventureWorks database.
using (SqlConnection sourceConnection =
new(connectionString))
{
sourceConnection.Open();
// Perform an initial count on the destination table.
SqlCommand commandRowCount = new(
"SELECT COUNT(*) FROM " +
"dbo.BulkCopyDemoMatchingColumns;",
sourceConnection);
long countStart = Convert.ToInt32(
commandRowCount.ExecuteScalar());
Console.WriteLine("Starting row count = {0}", countStart);
// Get data from the source table as a SqlDataReader.
SqlCommand commandSourceData = new(
"SELECT ProductID, Name, " +
"ProductNumber " +
"FROM Production.Product;", sourceConnection);
SqlDataReader reader =
commandSourceData.ExecuteReader();
// Open the destination connection. In the real world you would
// not use SqlBulkCopy to move data from one table to the other
// in the same database. This is for demonstration purposes only.
using (SqlConnection destinationConnection =
new(connectionString))
{
destinationConnection.Open();
// Set up the bulk copy object.
// Note that the column positions in the source
// data reader match the column positions in
// the destination table so there is no need to
// map columns.
using (SqlBulkCopy bulkCopy =
new(destinationConnection))
{
bulkCopy.DestinationTableName =
"dbo.BulkCopyDemoMatchingColumns";
try
{
// Write from the source to the destination.
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 = 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();
}
}
}
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.BulkCopyDemoMatchingColumns;", _
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 New SqlCommand( _
"SELECT ProductID, Name, ProductNumber " & _
"FROM Production.Product;", sourceConnection)
Dim reader As SqlDataReader = commandSourceData.ExecuteReader
' Open the destination connection. In the real world you would
' not use SqlBulkCopy to move data from one table to the other
' in the same database. This is for demonstration purposes only.
Using destinationConnection As SqlConnection = _
New SqlConnection(connectionString)
destinationConnection.Open()
' Set up the bulk copy object.
' The column positions in the source data reader
' match the column positions in the destination table,
' so there is no need to map columns.
Using bulkCopy As SqlBulkCopy = _
New SqlBulkCopy(destinationConnection)
bulkCopy.DestinationTableName = _
"dbo.BulkCopyDemoMatchingColumns"
Try
' Write from the source to the destination.
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 Using
End Sub
Private Function GetConnectionString() As String
Throw New NotImplementedException()
End Function
End Module
Performing a Bulk Copy Operation Using Transact-SQL and the Command Class
The following example illustrates how to use the ExecuteNonQuery method to execute the BULK INSERT statement.
Note
The file path for the data source is relative to the server. The server process must have access to that path in order for the bulk copy operation to succeed.
Using connection As SqlConnection = New SqlConnection(connectionString)
Dim queryString As String = _
"BULK INSERT Northwind.dbo.[Order Details] FROM " & _
"'f:\mydata\data.tbl' WITH (FORMATFILE='f:\mydata\data.fmt' )"
connection.Open()
SqlCommand command = New SqlCommand(queryString, connection);
command.ExecuteNonQuery()
End Using
using (SqlConnection connection = New SqlConnection(connectionString))
{
string queryString = "BULK INSERT Northwind.dbo.[Order Details] " +
"FROM 'f:\mydata\data.tbl' " +
"WITH ( FORMATFILE='f:\mydata\data.fmt' )";
connection.Open();
SqlCommand command = new SqlCommand(queryString, connection);
command.ExecuteNonQuery();
}