关于Ado.net批量的关键字

BulkCopy ：
   http://msdn.microsoft.com/en-us/library/system.data.sqlclient.sqlbulkcopy.aspx

kim - --- -
http://www.pin5i.com/showtopic-21934.html


批量删除:

   1、使用 Entity FrameWork  删除数据，着实是一件比较头疼的数据，若是少量数据，可以使用以下方法删除



using (DB.Entity.StudentDBEntities context = new DB.Entity.StudentDBEntities())
            {
                foreach (var item in context.Students.Where(row => row.Isleft == true))
                {
                    context.DeleteObject(item);
                }
                context.SaveChanges();
            }

2、但是若是要删除的数据有个三五万，10万20万那该如何，若采用上述方法，保守估计也得10分钟吧，不信，你可以写个程序，打开SQL Server Profiler试一下，这时，若你不想另外配置连接字符串，可以借用EF的连接字符串，使用ADO.Net 完成批量删除功能

.net Framework 3.5

public static void DeleteObject(SqlBtmsModel context, string deleteString)

{

    var bindingFlags = BindingFlags.Instance | BindingFlags.NonPublic;

    var factoryProperty = typeof(EntityConnection).GetProperty("StoreProviderFactory", bindingFlags);

    var factory = factoryProperty.GetValue(context.Connection, null) as DbProviderFactory;

    var connStr = (context.Connection as EntityConnection).StoreConnection.ConnectionString;

    using (var conn = factory.CreateConnection())

    {

        conn.ConnectionString = connStr;

        conn.Open();

        var cmd = factory.CreateCommand();

        cmd.Connection = conn;

        cmd.CommandText = deleteString;

        cmd.ExecuteNonQuery();

    }

}

Ø  .Net FrameWork 4.0

当然，若是你使用的是  .Net FrameWork 4.0,那你可以使用以下 方式。

using (DB.Entity.StudentDBEntities context = new DB.Entity.StudentDBEntities())
{

context.ExecuteStoreCommand("delete from Students where StudentId = @studentId", new SqlParameter("@studentId", 5));

context.ExecuteStoreCommand("insert into students (StudentName)values (@p1)", new SqlParameter("@p1", "test"));

}注：3.5不支持此方式。

可能有人，想使用EntityCommand 进行批量删除，但是EntityCommand 仅支持 EntitySql ，问题就在这里了，EntitySql 目前不支持 Insert 、Delete 、Update操作，静等微软的下一步动作吧。

C#中海量数据的批量插入和更新:

DateTime begin = DateTime.Now;
            string connectionString = "";
            using(SqlConnection conn = new SqlConnection(connectionString))...{
                conn.Open();

                SqlDataAdapter sd = new SqlDataAdapter();
                sd.SelectCommand = new SqlCommand("select top 200 devid,data_time,data_value from CurrentTest", conn);

                DataSet dataset = new DataSet();
                sd.Fill(dataset);
                Random r = new Random(1000);

                sd.UpdateCommand = new SqlCommand("update CurrentTest "
                                + " set data_time = @data_time,data_value = @data_value where devid = @devid", conn);
                sd.UpdateCommand.Parameters.Add("@data_time", SqlDbType.Char, 19, "data_time");
                sd.UpdateCommand.Parameters.Add("@data_value", SqlDbType.Int, 4, "data_value");
                sd.UpdateCommand.Parameters.Add("@devid", SqlDbType.Char, 20, "devid");
                sd.UpdateCommand.UpdatedRowSource = UpdateRowSource.None;
                sd.UpdateBatchSize = 0;
                for (int count = 0; count < 100000;)
                ...{

                    for (int i = 0; i < 200; i++,count++)
                    ...{
                        dataset.Tables[0].Rows[i].BeginEdit();
                        dataset.Tables[0].Rows[i]["data_time"] = "2222-22-22 22:22:22";
                        dataset.Tables[0].Rows[i]["data_value"] = 100;
                        dataset.Tables[0].Rows[i]["devid"] = "DEVID"+count;
                        dataset.Tables[0].Rows[i].EndEdit();
                    }
                    sd.Update(dataset.Tables[0]);
                }
 

                dataset.Tables[0].Clear();
                sd.Dispose();