writing to excel file from a two dimentional array VB.net - ms-office

I have a two dimentional array formed by iterating a data reader. Earlier i was using automation to write to excel and using range, i was able to write the contents of two dimentional array to excel in one shot. This improves the performance a lot because of only one interaction with excel. but came across a problem that my server does not have office installed, so am trying a different alternative using openxml(as i justneed to install only one dll in this case).
Online i saw few example of using the openxml, but i am not sure if there is a way to directly transfter the contents of two dimentional array to the worksheet. i don't want to iterate the datareader and update each cell by cell as i have 65 columns and almost 90000 rows.
So does the SDK offer any inbuild command to do this?

you should't fear the iteration because there's no longer an "interaction with excel" dcom penalty. The open xml is just writing to a stream, which you can buffer to save flushing to disk.
fyi i've personally used closed xml (nuget # http://nuget.org/packages/ClosedXML ) to create Excel files and found it much better than working with the raw Open XML standard.
finally, even if you had excel on the server you should never use excel as a dcom server in a no UI environment.

Related

How to select specific rows to load into an Excel Workbook from another at run-time

I have to .xlsx files. One has data "source.xlsx" and one has macros "work.xlsm". I can load the data from "source.xlsx" into "work.xlsm" using Excel's built-in load or using Application.GetOpenFilename. However, I don't want all the data in the source.xlsx. I only want to select specific rows, the criteria for which will be determined at run time.
Thinks of this as a SELECT from a database with parameters. I need to do this to limit the time and processing of the data being processed by "work.xlsx".
Is there a way to do that?
I tried using parameterized query from Excel --> [Data] --> [From Other Sources] but when I did that, it complained about not finding a table (same with ODBC). This is because the source has no table defined, so it makes sense. But I am restricted from touching the source.
So, In short, I need to filter data before exporting it in the target sheet without touching the source file. I want to do this either interactively or via a VBA macro.
Note: I am using Excel 2003.
Any help or pointers will be appreciated. Thx.
I used a macro to convert the source file from .xlsx to .csv format and then loaded the csv formatted file using a loop that contained the desired filter during the load.
This approach may not be the best, nevertheless, no other suggestion was offered and this one works!
The other approach is to abandon the idea of pre-filtering and sacrifice the load time delay and perform the filtering and removal of un-wanted rows in the "work.xlsm" file. Performance and memory size are major factors in this case, assuming code complexity is not the issue.

Consumer PowerPivot/Excel DataModel from another Excel file?

Short version: Is there any way/hack to use the embedded DataModel/PowerPivot cube of an Excel 2013/6 file from another Excel file?
Long version:
We have a large Excel Data Model with >400k rows and >100 measurements, feeding multiple reports (i.e. PivotTable on separate worksheets). As all this is growing, we want to split this out into a (large) data model and multiple reports. I know this could be done with SharePoint or PowerBI - however one of the key requirements is to be able to analyse the data offline. Hence, I'm trying to figure out any way to connect to the data model from another file....
There's no way that I know to do what you're asking. Is there any reason you can't just include all the reports in one workbook with the data model? Since you have to be able to analyze offline, anyway, everyone will need a local copy of the model. If the concern is just that there will be too many sheets in a single workbook, you could just put a thin veneer of VBA in it to hide and unhide sheets in groups for ease of use.
It looks like Microsoft has added an option to establish connection via ODC file.
See this f.e. https://learn.microsoft.com/en-us/sql/reporting-services/report-data/use-an-office-data-connection-odc-with-reports?view=sql-server-ver15
However it's not working out for me, I am using Excel 2016, exported data model from the file with data model as a separate odc file but when I try to add this as a connection in another file - I get the message - can't open the file. Looks like creating ODC file is not that straightforward.
Anyone had similar issues?

Excel Files and Visual Basic

I have never used Visual Basic before but could do with a pointer on where to begin.
I have 750 excel spreadsheets that contains various amounts of data of different types. The columns are always the same, but the number of data rows vary per spreadsheet. I need to extract data and put it into two new spreadsheets.
Obviously to do this 750 times manually would be a nightmare. I just want to run a script that can do it for me and thus thought of Visual Basic although i've never used it before.
My specific questions are:
What type of command should i research that would allow me to copy data where the row number to start at varies (as data above varies in no of rows). There is a title before this new data - how can i get it to search for this title and then choose the row below?
Would all my spreadsheets have to be in one folder so that the script goes through them all, or can i have some kind of folder structure in that folder too?
Anyone recommend any good resources for me to get to grips with visual basic and grasp what i need to do?
thanks
Tom
So the compilation task got easier with the introduction of MS PowerQuery. If you are using MS Excel 2013, you already have this. If no, you should download it and use the extension from MS.
The following guide outlines how to Using Power Query to Combine Data from Multiple Excel Files into One Table. This means that with Power Query (PQ), MS has taken and enabled easy aggregation using a few simple button clicks. PQ is a lightweight alternative to a lot of tasks that used to require VBA.
In this example, you will use PQ to point to an entire folder (750 should be no problem) worth of commonly formatted Excel files. The only limitation is that each data file should have a similarly named tab.
I won't repeat the details of the guide for how to do it, as it is in-depth and visual. But if you run into issues, get in touch.

Working with Office "open" XML - just how hard is it?

I'm considering replacing a (very) large body of Office-automation code with something that works with the Office XML format directly. I'm just starting out, but already I'm worried that it's too big a task.
I'll be dealing with Word, Excel and PowerPoint. So far I've only looked at Word and Excel. It looks like Word documents should be reasonably easy to manipulate, but Excel workbooks look like a nightmare. For example...
In Word, it looks like you could delete a paragraph simply by deleting the corresponding "w:p" tag. However, the supplied code snippet for deleting a row in Excel takes about 150 lines of code(!).
The reason the Excel code is so big is that deleting a row means updating the row indexes of all the subsequent rows, fixing up the "shared strings" table, etc. According to a comment at the top, the code snippet is not even complete, in that it won't deal with a workbook that has tables in it (I can live with that).
What I'm not clear on is whether that's the only restriction that the sample code has. For example, would there also be a problem if the workbook contained a Pivot Table? Or a chart that references data from the same sheet? Or some named ranges? Wouldn't you also have to update the formulae for any cells (etc.) that referenced a row whose row index had changed?
[That's not to mention the "calc chain", which (thankfully) I think you can simply delete since it's only a chache that can be re-built.]
And that's my question, woolly though it is. Just how hard do you have to work do something as simple as deleting a row properly? Is it an insurmountable task?
Also, if there are other, similar issues either with Excel or with Word or PowerPoint, I'd love to hear about them now, before I waste too much time going down a blind alley. Thanks.
Having worked with the Open XML SDK 2.0 for almost two years now I can say that doing seemingly trivial tasks can take many hours and sometimes days to figure out how to do it properly. For example, deleting an Excel row should be fairly straightforward and easy to do right? Nope because not only do you need code to delete your row, but then you have to update all the row indices, update any merged cell references, update hyperlink references, etc. Our internal delete method is close to 500 lines of code to just delete a row and I'm sure we don't have all the cases accounted for either.
The biggest complaint I have is the lack of documentation on how to do the most common tasks. The MSDN section on the Open XML SDK is very limited and whenever you need to do anything complicated you are really on your own. I've had to read the Open XML standard a lot to figure out what certain elements mean and how they should be implemented since I could find very little online.
The other challenging part is if you insert an element in a spot where it doesn't belong or put an invalid attribute on an element you will get a corrupt file when you try and open it. Most of the time you will not get any information on what caused the error and you will have to look at the Open XML standard spec to see what you did wrong.
If you need a fast turnaround time on converting that Office automation code into Open XML and what you are doing is not really basic, then I would say pass. If you have time and the patience to read up on the Word, Excel and PowerPoint XML structures and get familiar with how they relate then I say go for it. In my opinion it is really the only way to have very fine control over these office documents, but there will be a great learning curve when you start.
Oh and just for fun here is how much code is needed to add a comment to an Excel cell.
Just for completeness, here are some libraries I found for working with Excel XML:
www.extremexml.com - a layer on top of the Open XML SDK classes; focusses on injecting data into an existing spreadsheet; handles many of the cross-reference problems I identified in my question. Open source but GPL2 not LGPL. Code looks nice, and documentation is excellent. Does not appear terribly active on codeplex though.
Closed XML - another layer on top of the Open XML SDK - again open source, but with a less restrictive license (MIT). Looks nice, and looks more "active" than the above.
SpreadsheetLight - from what I can tell, a closed-source library sitting atop the Open XML SDK classes. Targeted more at those looking to create a spreadsheet from scratch rather than making changes to existing spreadsheets.
Here is another third party library dedicated to working with OpenXML:
http://www.officewriter.com
In the example cited by amurra above of deleting Excel spreadsheet rows, this is a single method call with this tool. It updates formulas and all the other references for which it seems that 500 lines of code would be required for otherwise.
The OpenXML SDK itself is a great tool for very simple things, but you still have to concern yourself with a lot of the internals of the file format and packaging structure to get things really right.
Here are some additional libraries that can manipulate with OOXML formats:
- GemBox.Spreadsheet (XLSX)
- GemBox.Document (DOCX)
Also GemBox published some articles that demonstrate how to manipulate with OOXML file format with pure .NET (without a use of any library), I think you'll find this interesting:
www.codeproject.com/Articles/15593/Read-and-write-Open-XML-files-MS-Office
(Introduction to SpreadsheetML format and an explanation on how we can read and write worksheet's cell content)
www.codeproject.com/Articles/649064/Show-Word-File-in-WPF
(Introduction to WordprocessingML format and demonstration on how we can read document's text)

Totaling figures in .csv files using Excel

I have 12 .csv files produced by another program. The .csv files contain numeric data, separated by commas.
I need an easy way of totaling the values in certain columns in each of the files and comparing the totals across the various files e.g. compare the total from file 1 to the total from file 5.
The format of each file is the same i.e. 5 values in each record, separated by commas. Each of the 12 .csv files is about 50 Mb in size. Each file has a different number of records.
The environment I work in is 'secure' and I cant run any programs other than what I have installed on the PC I use. I have Excel installed and assume I can write VBA code/macros and I have access to the Command line. I can't (for example) load anything from a USB key and can not install any scripting language e.g. Python.
I have thought of doing this manually e.g. open each .csv file in Excel and total the columns using Excel functions i.e. SUM()
My challenge I need to do this many times of the next few weeks as new versions of the .csv files are produced i.e. I now have the first version, there will be many versions of the 12 files produced as I conduct testing on the other system. For each new version I need to sum the data and compare across files.
Last thing to say is, I cant change the system that produces the .csv files e.g. to create a set of totals
I'm looking for a programming solution that I can use, given my limited resources (ability to use any tools other than what is already on the PC)
You should be able to do this easily using an excel VBA macro but it might take quite some time if it needs to load and convert a 50MB csv file.
JScript (a microsoft form of JavaScript) is generally available on all machines and runs under the windows scripting host. Just create a file with a .js extension and try to run with a double click. Or you can use vbscript with a .vbs extension.
I think your easiest solution would be to write an excel macro (as you will have the IDE for excel vba as limited as it is).
Powershell or a batch script? A CSV is nothing more than a text file split with commas. Should be fairly easy to knock something up.
ADO can work on CSV files and you could then use SQL statements to sum the appropriate values - see this MSDN article for full details.
If you go to the Visual Basic Editor in Excel then try to add a reference via the Tools menu you should have several for Microsoft ActiveX Data Objects (2.8 being the most recent one.) Adding that reference lets you use ADO.

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