Best Practices for Combining Data from Multiple Excel Files

In this video, we will learn some of the best practices to follow while combining data from multiple Excel files.

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===== WHO AM I? =====
A lot of people think that my name is Goodly, it's NOT ;)
My name is Chandeep. Goodly is my full-time venture where I share what I learn about Excel and Power BI.
Please browse around, you'll find a ton of interesting videos that I have created :) Cheers!

[kuuuyajim]

Some of these tips I picked up from different tutorials and some I was able to figure out myself. And indeed, they help improve refresh of the query. 😃

[jamesjacobslai]

For Folder Contents portion, could you create a tutorial on how to do it with Sharepoint Folder Path? Thank you for these tips! Very helpful!

[erzsebetbiro]

Dear Chandeep!

I suggest, You could also make additional videos on the power query optimization options as discussed in the video.

Please give me your suggestion. I have a problem with the notebook I use at my work. It has an old i3 cpu, 8GB of ram and use Office 365. Dozens of (currently 80 files) csv files need to be processed. Their individual file sizes are approx. 800 MB and the number of rows sometimes exceeds 1 million per file before cleaning. The files are distributed in directories. Imagine that there are cities, stores in the cities, products in the stores, and finally sales data for each product in the stores per customers.

Should I read the individual files and then combine them, or should I read the main library? Than filter the necessary data types?

Should I store the queries in memory or load them into excel pages? What if there are more rows than 1 million?

How should I handle large amounts of data?

Maybe I should switch to the MS Access program?
Or should I upload all csv files to SharePoint and read them from there with PoweQuery?

[emilmubarakshin]

These tips are absolutely essential and apply way over importing data from multiple csv/excel files. That’s what any sql, bi, data analyst should know and apply🎉

[MoonShine-bscl]

Awesome as alwys🎉 please can you make a video on snowflake database data load to power bi and best practices for handling huge database in power query... Thanks

[txreal]

Btw, I believe you can transform a subset of the data (like sample file in the transform step) with power query, then convert these power query applied steps into SQL to apply to the larger dataset.

[HachiAdachi]

Chandeep, did you say you can do **Incremental Refresh** when files are saved in SharePoint?! 🤯 Can you point to where I can learn how to do that because that would be a game changer for me!! 😁 Thanks!!

[afrovs]

It’s simpler to control formatting with xlsx files than csv - especially with leading 0’s

[hcaseres]

Hello Goodly, a question. Is it possible to generate a sheet automatically in Power Query? I have a table with a question number column and the rows are the answers. I want to separate the question numbers into sheets. Sheet="1" with all the answers to question 1, sheet="2" with all the answers to question 2... sheet =62 with all the answers to question 62.

[aleprv]

Hi! Very nice video. I have one question, what is the best approach to work with excel files that are generated in different languages?

[karthikeyankms]

Hi,
How to Save All the custom functions from one pbix file as a file and import those custom functions into other pbix files?

[shubhabratadey]

One small question. Even though csv is a better option than excel when it comes to raw data but their file sizes are quite higher than excel. In older Office, I have seen csv s to be quite smaller in sizes when I would convert them from Excel but it doesn't happen nowadays. How can we address this?

[exceldude]

how about savings excel files in binary - xlsb it help with refreshes

[mrbartuss]

I have a question. Do you have a video on how to get data from folder without combining the files, but creating separate queries for all of them?

[jofielalejandrosantaella]

Does PQ have some way to look how much space(?) does it take to execute each step?

[CiachoAcM]

How to merge multiple files, not combine? Do you know The solutions to merge more than 2 files/tables?

[alterchannel]

why isn't Folder.Contents showing in the intellisense? ok solved. the intellisense was not working well at all. I closed excel and opened it again and everything is normal again. Another Excel mystery

[farooqtahir]

So basically he is saying how to make things unnecessarily complicated