SqlBulkCopy 类
本文来自CSDN:http://msdn.microsoft.com/zh-cn/library/system.data.sqlclient.sqlbulkcopy(VS.80).aspx
MS SQL Server 提供一个称为 bcp 的流行的命令提示符实用工具,用于将数据从一个表移动到另一个表(表可以在不同服务器上)。
SqlBulkCopy 类允许编写提供类似功能的托管代码解决方案。相比其他将数据加载到 SQL Server 表的方法(例如 INSERT 语句), SqlBulkCopy 提供明显的性能优势。(经测试数据量越大性能越明显,至少是批量insert语句的25倍以上。)
使用 SqlBulkCopy 类只能向 SQL Server 表写入数据。但是数据源不限于 SQL Server,可以使用任何数据源,只要数据可加载到 DataTable 实例或可使用 IDataReader 实例读取数据。
SqlBulkcopy对象主要作为作为了提高批量插入的效率,所以在默认情况下批量数据的插入并不会引发insert触发器的触发。这可以通过使用SqlBulkCopy (String, SqlBulkCopyOptions) 指定enum SqlBulkCopyOptions为FireTriggers解决。
注意:使用SqlBulkcopy时在inserted表中是有多条记录的,且一次调用SqlBulkcopy只会有一次触发器的运行。
使用示例:
using System.Data.SqlClient;
class Program
{
static void Main()
{
string connectionString = "server=.;database=AdventureWorks;uid=sa;pwd=sa";
// 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();
}
}
}
}