CSV文件导入 [英] CSV File Import

问题描述

早上好，


我有一个问题，我将大型CSV导入Visual Studio 2005

- Visual Basic;一如既往，CSV的创建者已经在最终文件中包含了数据的详细信息（来自

开头的约160万条记录）。在我进行输入之前我正在对文件进行一些评估，目前这是通过读取所有行来完成的，直到

我到达最后然后返回最后10等行;有没有人知道

我怎么能从文件的底部读取，以便在我能够获得所需的数据之前否定读取过程的160万个b $ b周期。


我们非常感谢您提供的任何帮助。


您诚挚的，


William Foster


***通过开发人员指南 http： //www.developersdex.com ***

Good morning all,

I have an issue where I am importing a large CSV into Visual Studio 2005
- Visual Basic; as always the creators of the CSV have included the
details of the data at the end file (Some 1.6 million records from the
beginning). I am doing some evaluation on the file before I undertake
the importation, currently this is being done by reading all rows until
I get to the end then returning the last 10 or so rows; does anyone know
how I can read from the bottom of the file up to negate the 1.6 million
cycles of the read procedure before I can get to the data I need.

Any assistance you may be able to provide would be greatly appreciated.

Yours sincerely,

William Foster

*** Sent via Developersdex http://www.developersdex.com ***

推荐答案

William Foster写道：

William Foster wrote:

早上好，

我有一个问题，我将大型CSV导入Visual Studio 2005
- Visual Basic;一如既往，CSV的创建者已经在最终文件中包含了数据的详细信息（从
开始的约160万条记录）。在我进行输入之前，我正在对文件进行一些评估，目前这是通过读取所有行来完成的，直到
我到达最后然后返回最后10行左右;有没有人知道我怎么能从文件的底部读取，以便在我能够获得所需的数据之前否定160万次读取过程的周期。

非常感谢您提供的任何帮助。

您诚挚的，

William Foster

***通过Developersdex发送 http://www.developersdex.com ***

可能有一种更简单的方法，但我之前已经完成了这项工作，首先在二进制模式下打开文件

，因为CSV文件通常是行分隔的<通过CrLf（Hex 0D 0A）字符获得
，我从获取文件长度开始，然后向后读取
（使用SEEK）查找倒数第二个CrLf。


在倒数第二个和最后一个CrLf之间将是您的标题

您正在寻找的信息。


我相信这个虽然如前所述，也许有所帮助别人有一个

更好的方式。


ShaneO


有10种人 - 那些懂的人二元和那些

不要。

There''s probably a simpler way, but I''ve done it before by first opening
the file in Binary mode, and as CSV files are generally line-delimited
by CrLf (Hex 0D 0A) characters, I start by obtaining the file length and
reading backwards (using SEEK) to find the second-last CrLf.

Between the second-last and the last CrLf would be your header
information you were looking for.

I trust this helps, although as already said, maybe someone else has a
better way.

ShaneO

There are 10 kinds of people - Those who understand Binary and those who
don''t.

" William Foster" <无**** @ devdex.com>在留言中写道

新闻：％2 *************** @ TK2MSFTNGP12.phx.gbl ...

"William Foster" <no****@devdex.com> wrote in message
news:%2***************@TK2MSFTNGP12.phx.gbl...

早上好，

我有一个问题，我将大型CSV导入Visual Studio 2005
- Visual Basic;一如既往，CSV的创建者已经在最终文件中包含了数据的详细信息（从
开始的约160万条记录）。在我进行输入之前，我正在对文件进行一些评估，目前这是通过读取所有行来完成的，直到
我到达最后然后返回最后10行左右;有没有人知道我怎么能从文件的底部读取，以便在我得到我需要的数据之前否定读取过程的160万个周期。

Good morning all,

I have an issue where I am importing a large CSV into Visual Studio 2005
- Visual Basic; as always the creators of the CSV have included the
details of the data at the end file (Some 1.6 million records from the
beginning). I am doing some evaluation on the file before I undertake
the importation, currently this is being done by reading all rows until
I get to the end then returning the last 10 or so rows; does anyone know
how I can read from the bottom of the file up to negate the 1.6 million
cycles of the read procedure before I can get to the data I need.

您是否尝试过MSWord？

Have you tried MSWord?

Shane，


感谢您的协助，我会给予那个去吧，听起来有点尴尬，但它比我做的好多了。


谢谢！


你真诚的，


William Foster


***通过Developersdex发送 http://www.developersdex.com ***

Shane,

Thanks for your assistance, I will give that a go, it sounds a bit
awkward, but it is much better than the way I am doing it.

Thank you !

Yours sincerely,

William Foster

*** Sent via Developersdex http://www.developersdex.com ***

这篇关于CSV文件导入的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！