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การเข้าถึงหน้านี้ต้องได้รับการอนุญาต คุณสามารถลองเปลี่ยนไดเรกทอรีได้
Bulk copy operations can be performed as isolated operations or as part of a multiple step transaction. This latter option enables you to perform more than one bulk copy operation within the same transaction, as well as perform other database operations (such as inserts, updates, and deletes) while still being able to commit or roll back the entire transaction.
By default, a bulk copy operation runs without a transaction that the client can roll back. To roll back all or part of a copy after an error, specify SqlBulkCopyOptions.UseInternalTransaction for per-batch transactions, use an existing SqlTransaction, or enlist the connection in Transaction.
Performing a Non-transacted Bulk Copy Operation
The following Console application shows what happens when a non-transacted bulk copy operation encounters an error partway through the operation.
In the example, the source table and destination table each include an Identity column named ProductID. The code first prepares the destination table by deleting all rows and then inserting a single row whose ProductID is known to exist in the source table. By default, a new value for the Identity column is generated in the destination table for each row added. In this example, an option is set when the connection is opened that forces the bulk load process to use the Identity values from the source table instead.
The bulk copy operation is executed with the BatchSize property set to 10. When the operation encounters the invalid row, an exception is thrown. In this first example, the bulk copy operation is non-transacted. All batches copied up to the point of the error are committed; the batch containing the duplicate key is rolled back, and the bulk copy operation is halted before processing any other batches.
Note
Before you run this sample, create the work tables described in Bulk Copy Example Setup. The sample demonstrates SqlBulkCopy syntax. If the source and destination tables are in the same SQL Server instance, use a Transact-SQL (T-SQL) INSERT ... SELECT statement for a faster copy.
var connectionString = GetConnectionString();
// Open a sourceConnection to the AdventureWorks database.
using (SqlConnection sourceConnection =
new(connectionString))
{
sourceConnection.Open();
// Delete all from the destination table.
SqlCommand commandDelete = new()
{
Connection = sourceConnection,
CommandText =
"DELETE FROM dbo.BulkCopyDemoMatchingColumns"
};
commandDelete.ExecuteNonQuery();
// Add a single row that will result in duplicate key
// when all rows from source are bulk copied.
// Note that this technique will only be successful in
// illustrating the point if a row with ProductID = 446
// exists in the AdventureWorks Production.Products table.
// If you have made changes to the data in this table, change
// the SQL statement in the code to add a ProductID that
// does exist in your version of the Production.Products
// table. Choose any ProductID in the middle of the table
// (not first or last row) to best illustrate the result.
SqlCommand commandInsert = new()
{
Connection = sourceConnection,
CommandText =
"SET IDENTITY_INSERT dbo.BulkCopyDemoMatchingColumns ON;" +
"INSERT INTO " + "dbo.BulkCopyDemoMatchingColumns " +
"([ProductID], [Name] ,[ProductNumber]) " +
"VALUES(446, 'Lock Nut 23','LN-3416');" +
"SET IDENTITY_INSERT dbo.BulkCopyDemoMatchingColumns OFF"
};
commandInsert.ExecuteNonQuery();
// 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($"Starting row count = {countStart}");
// Get data from the source table as a SqlDataReader.
SqlCommand commandSourceData = new(
"SELECT ProductID, Name, ProductNumber " +
"FROM Production.Product;", sourceConnection);
SqlDataReader reader = commandSourceData.ExecuteReader();
// Set up the bulk copy object using the KeepIdentity option.
using (SqlBulkCopy bulkCopy = new(
connectionString, SqlBulkCopyOptions.KeepIdentity))
{
bulkCopy.BatchSize = 10;
bulkCopy.DestinationTableName =
"dbo.BulkCopyDemoMatchingColumns";
// Write from the source to the destination.
// This should fail with a duplicate key error
// after some of the batches have been copied.
try
{
bulkCopy.WriteToServer(reader);
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
finally
{
reader.Close();
}
}
// Perform a final count on the destination
// table to see how many rows were added.
long countEnd = Convert.ToInt32(
commandRowCount.ExecuteScalar());
Console.WriteLine($"Ending row count = {countEnd}");
Console.WriteLine($"{countEnd - countStart} rows were added.");
Console.WriteLine("Press Enter to finish.");
Console.ReadLine();
}
Imports Microsoft.Data.SqlClient
Module Module1
Sub Main()
Dim connectionString As String = GetConnectionString()
' Open a sourceConnection to the AdventureWorks database.
Using sourceConnection As SqlConnection = _
New SqlConnection(connectionString)
sourceConnection.Open()
' Delete all from the destination table.
Dim commandDelete As New SqlCommand
commandDelete.Connection = sourceConnection
commandDelete.CommandText = _
"DELETE FROM dbo.BulkCopyDemoMatchingColumns"
commandDelete.ExecuteNonQuery()
' Add a single row that will result in duplicate key
' when all rows from source are bulk copied.
' Note that this technique will only be successful in
' illustrating the point if a row with ProductID = 446
' exists in the AdventureWorks Production.Products table.
' If you have made changes to the data in this table, change
' the SQL statement in the code to add a ProductID that
' does exist in your version of the Production.Products
' table. Choose any ProductID in the middle of the table
' (not first or last row) to best illustrate the result.
Dim commandInsert As New SqlCommand
commandInsert.Connection = sourceConnection
commandInsert.CommandText = _
"SET IDENTITY_INSERT dbo.BulkCopyDemoMatchingColumns ON;" & _
"INSERT INTO dbo.BulkCopyDemoMatchingColumns " & _
"([ProductID], [Name] ,[ProductNumber]) " & _
"VALUES(446, 'Lock Nut 23','LN-3416');" & _
"SET IDENTITY_INSERT dbo.BulkCopyDemoMatchingColumns OFF"
commandInsert.ExecuteNonQuery()
' 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 SqlCommand = New SqlCommand( _
"SELECT ProductID, Name, ProductNumber " & _
"FROM Production.Product;", sourceConnection)
Dim reader As SqlDataReader = _
commandSourceData.ExecuteReader()
' Set up the bulk copy object using the KeepIdentity option.
Using bulkCopy As SqlBulkCopy = New SqlBulkCopy(connectionString, _
SqlBulkCopyOptions.KeepIdentity)
bulkCopy.BatchSize = 10
bulkCopy.DestinationTableName = "dbo.BulkCopyDemoMatchingColumns"
' Write from the source to the destination.
' This should fail with a duplicate key error
' after some of the batches have already been copied.
Try
bulkCopy.WriteToServer(reader)
Catch ex As Exception
Console.WriteLine(ex.Message)
Finally
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
Throw New NotImplementedException()
End Function
End Module
Performing a Dedicated Bulk Copy Operation in a Transaction
To let SqlBulkCopy manage a separate transaction for each batch, specify UseInternalTransaction. Use a connection string or an existing connection without an active transaction.
Pass this option to the SqlBulkCopy constructor. The copy commits each completed batch independently rather than treating the entire operation as one transaction.
Note
Since different batches are executed in different transactions, if an error occurs during the bulk copy operation, all the rows in the current batch will be rolled back, but rows from previous batches will remain in the database.
The following console application is similar to the previous example, with one exception: In this example, the bulk copy operation manages its own transactions. All batches copied up to the point of the error are committed; the batch containing the duplicate key is rolled back, and the bulk copy operation is halted before processing any other batches.
Important
Before you run this sample, create the work tables described in Bulk Copy Example Setup. The sample demonstrates SqlBulkCopy syntax. If the source and destination tables are in the same SQL Server instance, use a Transact-SQL INSERT ... SELECT statement for a faster copy.
var connectionString = GetConnectionString();
// Open a sourceConnection to the AdventureWorks database.
using (SqlConnection sourceConnection =
new(connectionString))
{
sourceConnection.Open();
// Delete all from the destination table.
SqlCommand commandDelete = new()
{
Connection = sourceConnection,
CommandText =
"DELETE FROM dbo.BulkCopyDemoMatchingColumns"
};
commandDelete.ExecuteNonQuery();
// Add a single row that will result in duplicate key
// when all rows from source are bulk copied.
// Note that this technique will only be successful in
// illustrating the point if a row with ProductID = 446
// exists in the AdventureWorks Production.Products table.
// If you have made changes to the data in this table, change
// the SQL statement in the code to add a ProductID that
// does exist in your version of the Production.Products
// table. Choose any ProductID in the middle of the table
// (not first or last row) to best illustrate the result.
SqlCommand commandInsert = new()
{
Connection = sourceConnection,
CommandText =
"SET IDENTITY_INSERT dbo.BulkCopyDemoMatchingColumns ON;" +
"INSERT INTO " + "dbo.BulkCopyDemoMatchingColumns " +
"([ProductID], [Name] ,[ProductNumber]) " +
"VALUES(446, 'Lock Nut 23','LN-3416');" +
"SET IDENTITY_INSERT dbo.BulkCopyDemoMatchingColumns OFF"
};
commandInsert.ExecuteNonQuery();
// 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 = {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();
// Set up the bulk copy object.
// Note that when specifying the UseInternalTransaction
// option, you cannot also specify an external transaction.
// Therefore, you must use the SqlBulkCopy construct that
// requires a string for the connection, rather than an
// existing SqlConnection object.
using (SqlBulkCopy bulkCopy = new(
connectionString, SqlBulkCopyOptions.KeepIdentity |
SqlBulkCopyOptions.UseInternalTransaction))
{
bulkCopy.BatchSize = 10;
bulkCopy.DestinationTableName =
"dbo.BulkCopyDemoMatchingColumns";
// Write from the source to the destination.
// This should fail with a duplicate key error
// after some of the batches have been copied.
try
{
bulkCopy.WriteToServer(reader);
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
finally
{
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($"Ending row count = {countEnd}");
Console.WriteLine($"{countEnd - countStart} rows were added.");
Console.WriteLine("Press Enter to finish.");
Console.ReadLine();
}
Imports Microsoft.Data.SqlClient
Module Module1
Sub Main()
Dim connectionString As String = GetConnectionString()
' Open a sourceConnection to the AdventureWorks database.
Using sourceConnection As SqlConnection = _
New SqlConnection(connectionString)
sourceConnection.Open()
' Delete all from the destination table.
Dim commandDelete As New SqlCommand
commandDelete.Connection = sourceConnection
commandDelete.CommandText = _
"DELETE FROM dbo.BulkCopyDemoMatchingColumns"
commandDelete.ExecuteNonQuery()
' Add a single row that will result in duplicate key
' when all rows from source are bulk copied.
' Note that this technique will only be successful in
' illustrating the point if a row with ProductID = 446
' exists in the AdventureWorks Production.Products table.
' If you have made changes to the data in this table, change
' the SQL statement in the code to add a ProductID that
' does exist in your version of the Production.Products
' table. Choose any ProductID in the middle of the table
' (not first or last row) to best illustrate the result.
Dim commandInsert As New SqlCommand
commandInsert.Connection = sourceConnection
commandInsert.CommandText = _
"SET IDENTITY_INSERT dbo.BulkCopyDemoMatchingColumns ON;" & _
"INSERT INTO dbo.BulkCopyDemoMatchingColumns " & _
"([ProductID], [Name] ,[ProductNumber]) " & _
"VALUES(446, 'Lock Nut 23','LN-3416');" & _
"SET IDENTITY_INSERT dbo.BulkCopyDemoMatchingColumns OFF"
commandInsert.ExecuteNonQuery()
' 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 SqlCommand = New SqlCommand( _
"SELECT ProductID, Name, ProductNumber " & _
"FROM Production.Product;", sourceConnection)
Dim reader As SqlDataReader = _
commandSourceData.ExecuteReader()
' Set up the bulk copy object.
' Note that when specifying the UseInternalTransaction option,
' you cannot also specify an external transaction. Therefore,
' you must use the SqlBulkCopy construct that requires a string
' for the connection, rather than an existing SqlConnection object.
Using bulkCopy As SqlBulkCopy = New SqlBulkCopy(connectionString, _
SqlBulkCopyOptions.UseInternalTransaction Or _
SqlBulkCopyOptions.KeepIdentity)
bulkCopy.BatchSize = 10
bulkCopy.DestinationTableName = "dbo.BulkCopyDemoMatchingColumns"
' Write from the source to the destination.
' This should fail with a duplicate key error
' after some of the batches have already been copied.
Try
bulkCopy.WriteToServer(reader)
Catch ex As Exception
Console.WriteLine(ex.Message)
Finally
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
Throw New NotImplementedException()
End Function
End Module
Using Existing Transactions
Pass the existing SqlTransaction object to the SqlBulkCopy constructor to include the copy in that transaction. The bulk copy doesn't commit or roll back the transaction. Your application controls the transaction, including any other database operations it contains. If the connection has an active transaction but you pass a null transaction reference, the provider throws an exception.
To roll back the entire copy after an error, or include it in a larger operation that you can roll back, provide the SqlTransaction object to the SqlBulkCopy constructor.
The following console application is similar to the first (non-transacted) example, with one exception: in this example, the bulk copy operation is included in a larger, external transaction. When the primary key violation error occurs, the entire transaction is rolled back and no rows are added to the destination table.
Important
Before you run this sample, create the work tables described in Bulk Copy Example Setup. The sample demonstrates SqlBulkCopy syntax. If the source and destination tables are in the same SQL Server instance, use a Transact-SQL INSERT ... SELECT statement for a faster copy.
var connectionString = GetConnectionString();
// Open a sourceConnection to the AdventureWorks database.
using (SqlConnection sourceConnection =
new(connectionString))
{
sourceConnection.Open();
// Delete all from the destination table.
SqlCommand commandDelete = new()
{
Connection = sourceConnection,
CommandText =
"DELETE FROM dbo.BulkCopyDemoMatchingColumns"
};
commandDelete.ExecuteNonQuery();
// Add a single row that will result in duplicate key
// when all rows from source are bulk copied.
// Note that this technique will only be successful in
// illustrating the point if a row with ProductID = 446
// exists in the AdventureWorks Production.Products table.
// If you have made changes to the data in this table, change
// the SQL statement in the code to add a ProductID that
// does exist in your version of the Production.Products
// table. Choose any ProductID in the middle of the table
// (not first or last row) to best illustrate the result.
SqlCommand commandInsert = new()
{
Connection = sourceConnection,
CommandText =
"SET IDENTITY_INSERT dbo.BulkCopyDemoMatchingColumns ON;" +
"INSERT INTO " + "dbo.BulkCopyDemoMatchingColumns " +
"([ProductID], [Name] ,[ProductNumber]) " +
"VALUES(446, 'Lock Nut 23','LN-3416');" +
"SET IDENTITY_INSERT dbo.BulkCopyDemoMatchingColumns OFF"
};
commandInsert.ExecuteNonQuery();
// 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($"Starting row count = {countStart}");
// Get data from the source table as a SqlDataReader.
SqlCommand commandSourceData = new(
"SELECT ProductID, Name, ProductNumber " +
"FROM Production.Product;", sourceConnection);
SqlDataReader reader = commandSourceData.ExecuteReader();
//Set up the bulk copy object inside the transaction.
using (SqlConnection destinationConnection =
new(connectionString))
{
destinationConnection.Open();
using (SqlTransaction transaction =
destinationConnection.BeginTransaction())
{
using (SqlBulkCopy bulkCopy = new(
destinationConnection, SqlBulkCopyOptions.KeepIdentity,
transaction))
{
bulkCopy.BatchSize = 10;
bulkCopy.DestinationTableName =
"dbo.BulkCopyDemoMatchingColumns";
// Write from the source to the destination.
// This should fail with a duplicate key error.
try
{
bulkCopy.WriteToServer(reader);
transaction.Commit();
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
transaction.Rollback();
}
finally
{
reader.Close();
}
}
}
}
// Perform a final count on the destination
// table to see how many rows were added.
long countEnd = Convert.ToInt32(
commandRowCount.ExecuteScalar());
Console.WriteLine($"Ending row count = {countEnd}");
Console.WriteLine($"{countEnd - countStart} rows were added.");
Console.WriteLine("Press Enter to finish.");
Console.ReadLine();
}
Imports Microsoft.Data.SqlClient
Module Module1
Sub Main()
Dim connectionString As String = GetConnectionString()
' Open a sourceConnection to the AdventureWorks database.
Using sourceConnection As SqlConnection = _
New SqlConnection(connectionString)
sourceConnection.Open()
' Delete all from the destination table.
Dim commandDelete As New SqlCommand
commandDelete.Connection = sourceConnection
commandDelete.CommandText = _
"DELETE FROM dbo.BulkCopyDemoMatchingColumns"
commandDelete.ExecuteNonQuery()
' Add a single row that will result in duplicate key
' when all rows from source are bulk copied.
' Note that this technique will only be successful in
' illustrating the point if a row with ProductID = 446
' exists in the AdventureWorks Production.Products table.
' If you have made changes to the data in this table, change
' the SQL statement in the code to add a ProductID that
' does exist in your version of the Production.Products
' table. Choose any ProductID in the middle of the table
' (not first or last row) to best illustrate the result.
Dim commandInsert As New SqlCommand
commandInsert.Connection = sourceConnection
commandInsert.CommandText = _
"SET IDENTITY_INSERT dbo.BulkCopyDemoMatchingColumns ON;" & _
"INSERT INTO dbo.BulkCopyDemoMatchingColumns " & _
"([ProductID], [Name] ,[ProductNumber]) " & _
"VALUES(446, 'Lock Nut 23','LN-3416');" & _
"SET IDENTITY_INSERT dbo.BulkCopyDemoMatchingColumns OFF"
commandInsert.ExecuteNonQuery()
' 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 SqlCommand = New SqlCommand( _
"SELECT ProductID, Name, ProductNumber " & _
"FROM Production.Product;", sourceConnection)
Dim reader As SqlDataReader = _
commandSourceData.ExecuteReader()
' Set up the bulk copy object inside the transaction.
Using destinationConnection As SqlConnection = _
New SqlConnection(connectionString)
destinationConnection.Open()
Using transaction As SqlTransaction = _
destinationConnection.BeginTransaction()
Using bulkCopy As SqlBulkCopy = New _
SqlBulkCopy(destinationConnection, _
SqlBulkCopyOptions.KeepIdentity, transaction)
bulkCopy.BatchSize = 10
bulkCopy.DestinationTableName = _
"dbo.BulkCopyDemoMatchingColumns"
' Write from the source to the destination.
' This should fail with a duplicate key error.
Try
bulkCopy.WriteToServer(reader)
transaction.Commit()
Catch ex As Exception
Console.WriteLine(ex.Message)
transaction.Rollback()
Finally
reader.Close()
End Try
End Using
End Using
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
Throw New NotImplementedException()
End Function
End Module