Anyone share the structure of Excel 2003 ( xls ), 2007 ( xlsx ) files?

Question

Delphi

Can't find doc. according to the description of the structure of these files. I found it in English - two problems:
I didn’t understand anything, it’s only xls.
I need to export data, only export. The size of the Excel files is too large, if done through OLE, then the reading process takes a very, very long time. YES, and besides, I still need to remove duplicates.
Here decided to write a class which reads the data directly.

Answer 1

Here, a friend in PHP pulled something from xlsx: habrahabr.ru/post/140352 . If your file is as simple as possible a table, then it will probably be possible to read it. But if there are formulas, links, design is different, then it will be more difficult. At least the price of the components that do this is not in vain small.

Answer 2

xlsx format files and anything ending in "x" is an implementation of Open XML.
The structure of such files is a zip archive, but instead of *.zip, it has the extension *xlsx, *docx, etc. If you change the file extension to .zip, you can see its structure. In general xlsx is a zipped folder which contains folders, xml and other files.
Open XML for Office
Open XML SDK

Answer 3

The starting point for the formats of the "old" office (doc, xls and much more) - https://msdn.microsoft.com/ru-ru/library/dd942138.aspx
Further on specific formats, a couple of thousand pages.

Answer 4

habrahabr.ru/post/110019
habrahabr.ru/post/254541