SqlBulkCopy Generic List<T>

gistfile1.cs

public static class SqlBulkCopyForDapper
{
	public static void BulkInsert<T>(this IDbConnection connection, IList<T> list)
	{
		var conn = connection as SqlConnection;

		if (conn == null)
			throw new Exception("conn is not SQLConnection");

		if(conn.State !=  ConnectionState.Open)
			conn.Open();

		using (var bulkCopy = new SqlBulkCopy(conn))
		{
			bulkCopy.BatchSize = list.Count;
			bulkCopy.DestinationTableName = typeof(T).Name;

			var table = new DataTable();
			var props = TypeDescriptor.GetProperties(typeof(T))
				//Dirty hack to make sure we only have system data types 
				//i.e. filter out the relationships/collections
				.Cast<PropertyDescriptor>()
				.Where(propertyInfo => propertyInfo.PropertyType.Namespace.Equals("System"))
				.ToArray();

			foreach (var propertyInfo in props)
			{
				bulkCopy.ColumnMappings.Add(propertyInfo.Name, propertyInfo.Name);
				table.Columns.Add(propertyInfo.Name, Nullable.GetUnderlyingType(propertyInfo.PropertyType) ?? propertyInfo.PropertyType);
			}

			var values = new object[props.Length];
			foreach (var item in list)
			{
				for (var i = 0; i < values.Length; i++)
				{
					values[i] = props[i].GetValue(item);
				}

				table.Rows.Add(values);
			}

			bulkCopy.WriteToServer(table);
		}
	}
}