Excel Power Query is amazing, and powerful, and a fabulous tool for anyone serious about getting data in or out of Salesforce.

Unfortunately if you use a OSx you are out of luck. Try installing windows in a VM just to get Power Query goodness.

I will go through a few scenarios with examples and screen shots of how to use Power Query simply.

There is so much you can do with Power Query, and it's related product Power BI, but I am only scratching the surface.

Download

Power Query is a free download from Microsoft for Office 2010 and 2013 running on Windows 7 plus. I am running Office 2010 on Windows 7 64 bit at the moment and it is working great.

Download it here https://www.microsoft.com/en-au/download/details.aspx?id=39379

What I love about Power Query

It's almost like my first programming love - Excel 4 macro language (XLM). This is the programming language I taught myself on, which is probably why I'm not much of a coder now. http://www.brighthub.com/computing/windows-platform/articles/84345.aspx
You just do things in the workbook and it records what you are doing
You can go back and edit earlier steps
You can rename steps to document as you go
You can insert new steps
You can do very powerful functions or very simple things.
You can repeat and repeat over and over again without losing the source data. It is so cool!
You can run Salesforce reports right in Excel! Whenever you open up the spreadsheet there it is - your latest data * (caveats apply, as per usual).

Uses

When doing a major import into Salesforce, you will want to do more than one import - eg one into the sandbox, and one into live. The data will change in that time frame. Power Query allows you to clean up the data once, then when the new export is done just before go-live you can run the power query again to format the new data.
You can practice practice practice and get more and more sophisticated with your data cleansing
You should be able to do a good dedupe before importing the main data.

Import

Here's the scenario. (This is a real scenario, but I'm using sample data to protect the innocent).

I have a heap of data I need to import into Salesforce, and it is coming from another horrible database that has no data validation and has suffered years of neglect. The current situation is that they need to import the data into Salesforce on a weekly basis and import ALL the data because their database has no way of exporting just the new or updated records (I know, right??!?!? - People who work on these sort of databases need to reevaluate their life choices, I reckon).

The data horrors that need to be cleaned in this data set include:

Deleting unneeded columns
Extracting the year from the date field because the dates are not entered in a consistent way
Merging 3 columns into one separated by semicolons so they go into a multi select picklist.
Making all the ID numbers the same length by prepending zeros
Data consistency eg Female entered as Female, female, f, F or fem.
V-Lookups to replace data
Combine the area code and the phone number into one field and attempt to format it nicely.
Ensure all the states are entered as abbreviations rather than full words
Ensure Countries are entered as Australia and not Aus
Turn yes and no values into true and false (or 1 and 0)
Remove duplicate records
Remove test or dummy data (entered with an ID number beginning with Z - at least it is easy to find).

Things you could also do:

Check for valid email addresses using regex
Try to turn phone numbers into international format (though this is difficult and would only be useful if you have a limited set of data - eg you know the majority of your entries are Australian).
Merge two lists into one.
Separate out the data into separate import files for Accounts and Contacts. (I'm using Skyvva so I don't need to do that in this instance).

So, all of this would take around 20 mins to do by hand every week. With Power Query it takes about 1 minute, and that's just to paste in the data from the downloaded spreadsheet, and run the query.

Sample Data

I'm using the Sample Data I found for a temporal data set of employees. This is a data set that contains the full history of employee data over time. In this scenario we want to bring the employees in as contacts (yes, I know, that might not be what you would do in real life), and the old historic data will stay in the old system (again, may not happen in real life).

The sample data - we can see that the start and end date appear for every data point. We will simplify this data to produce just a list of employees, their departments.

Steps

Open the Power Query Ribbon
Click From Table
First we want to get rid of the data we don't need - so all the tend and start columns
Just go right ahead and delete the columns - don't be afraid, you won't damage anything!
- Right Click on the column heading > Remove.
That looks better already
Now see the side panel to see what it has done.
- It's a good idea to rename Removed Columns to something more descriptive.
- eg Removed date columns
Now Change M and F to Male and Female
- Right click on the sex column
  - Replace Values
  - Value to Find = M
  - Replace with = Male
  - Match entire cell contents = true
- Oops, I made a mistake - I typed replace M with F. Ok that's easy.
  - Just click the X next to Replaced Value in the panel and start again
- Oops, another mistake - I typed Femals rater than Female. Easy.
  - Just click the cog next to the action in the side panel and make the adjustment
- Again rename your labels in the side panel
- Now, if you have more than a few values you won't use find ad replace.
Notice how some steps get combined (eg all the deletions) and some steps get added as each one (eg the replacements).
At this stage look at the advanced editor so you can see what is happening
- Click Advanced Editor in the ribbon.
- You can edit this, but beware it does get confusing with a big data set.
Now, let's format the dates
- The date format depends on which data loader you use to do the Import.
- We will use MM\DD\YYYY
Right click on birthdate
- Choose Change Type > Date > By Locale
- Choose Date then English (United States)

Export

Again a real scenario. My client has KPIs on number of cases answered per month. They want to do a chart to present to management overlaying KPIs with the count of Cases for the year, by quarter. How can you do that in Salesforce. It is virtually impossible (Well, there may be a big hack way of doing it, but I have not found one. The new Charts from Apsona may be able to do it http://apsona.com/pages/sfdc/apsona-charting.html).

I ended up using http://www.klipfolio.com/ which is a brilliant brilliant, and cheap solution. But Klipfolio has a very high learning curve and is not for your average punter.

I want to replicate this in Excel using Power Query.

Excel Power Query