ADO vs ADO .NET and Data Transfer

Question

Hello I am looking for the fastest method of data transfer using C#. I want to extract a large amount of data from a table using a make table query to create a local table on a user machine. I am currently using ADO and the firehose cursor (forward looking read only). I was just wondering if there is a faster way to accomplish this. I am also doing something similar in VB6 and was wondering if I would see a noticeable perfomance boost if I upgraded the application to C#. Any thoughts would be great. Thanks

Munna Sarfraz · Answer

Microsoft SQL Server includes a popular command-prompt utility named bcp for moving data from one table to another whether on a single server or between servers. The SqlBulkCopy class lets you write managed code solutions that provide similar functionality. There are other ways to load data into a SQL Server table (INSERT statements for example) but SqlBulkCopy offers a significant performance advantage over them. The SqlBulkCopy class can be used to write data only to SQL Server tables. However the data source is not limited to SQL Server; any data source can be used as long as the data can be loaded to a DataTable instance or read with a IDataReader instance. Example Visual Basic 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 SqlCommand = 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 ' 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; End Function End Module C# 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)) { sourceConnection.Open(); // Perform an initial count on the destination table. SqlCommand commandRowCount = new SqlCommand( SELECT COUNT(*) FROM  + dbo.BulkCopyDemoMatchingColumns;  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(); // 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 SqlConnection(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 SqlBulkCopy(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 = 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; ; } }

Mahesh Chand · Answer

If you are using .NET 2.0 look for SqlBulkCopy. Also look for DataTable.ImportRow. Check out ADO.NET section of this site or search of SqlBulkCopy. Also you can execute SQL query INSERT INTO ... SELECT FROM.