Six reasons to start learning SQL

This is a guest post from Tomi Mester of Data36.

Back in 2011, during my college years, I got my first-ever job (an internship) at a cool IT startup. I got to do all kinds of interesting tasks but mostly it was data analysis.

The process was simple:

  • I received data from the developers in .csv format
  • I imported it into Excel
  • I crunched the data there
  • I sent the beautiful charts to my manager

We learned a lot about user behaviour, trends, and how we reached (or didn’t reach) our goals. I loved it – except for one thing: I always had to wait days (sometimes weeks) for the developers to export the data for me from the company’s SQL database.

That was my #1 reason to learn SQL!

I did so. And ever since then Iโ€™ve been a huge fan of this simple and elegant data language.


Because knowing SQL allowed me to do better, more detailed data analyses – more easily and faster. And I strongly believe that it can be extremely useful for everyone else who works in data analytics and who uses different spreadsheet tools in their day-to-day job.

In this article, I’ll give you 6 reasons why you should learn SQL too!
Continue reading Six reasons to start learning SQL

How we manage our family finances with Google Sheets

“If you can’t measure it, you can’t improve it.” – Peter Drucker

Disclosure: Some of the links in this post are affiliate links, meaning I’ll get a small commission (at no extra cost to you) if you signup.

Trying to have conversations about saving, spending and planning for retirement is infinitely more difficult and more stressful without accurate numbers in front of you.

You fall back on anecdotes and feelings because you have nothing else to go on.

Conversations start with phrases like: “it feels like we haven’t spent much on eating out this month” and they don’t get any better from there.

My wife and I have two beautiful boys, aged 1 and 3, and we’re both ambitious with our careers and work full-time. Life is crazy, crazy busy for us right now.

We’ve found it challenging to find time to manage our family finances, so we’ve been in this position of flying blind without a financial tracking plan in place. We’ve had those frustrating conversations, knowing that if we had better insights into our financial habits we could do a much better job at financial planning.

I want to show you how we changed that.

How we created a system in Google Sheets for tracking our spending habits.

It now only takes us about 10 or 15 minutes each week, so we can focus on understanding our financial situation better, and maximize our saving.

Enter Tiller

Tiller is an amazing tool that connects our bank accounts and credit cards securely to Google Sheets (or Excel), and automatically updates them on a daily basis.

It means we can see all of our financial transactions in one place and do our own custom analysis in Google Sheets.

Tiller Google Sheets

It’s been transformative for our family’s sanity and helped us get on top of our spending and hit our saving goals.

Tiller has a suite of Google Sheet templates available too, covering spending, saving, budgeting and net worth tracking, so that you can visualize your financial data immediately.

Of course, you can also build your own solutions to answer whatever questions you have.

It costs $59/year, which is tremendous value since you’re getting a fully customizable, automated personal finance tool.

How to setup Tiller with Google Sheets

Tiller is a third-party tool so you have to create an account with them, which is done securely through your Google account credentials.

This is what your homepage looks like, and where you add accounts or create new Google Sheet templates:

Tiller dashboard

Once you add the bank accounts and credit cards you want to track, you can go ahead and create a new Google Sheet:

Create new Google Sheet with Tiller
1. Name the Sheet
2. Choose a template or just the data
3. Select which accounts to include

Click Create and the magic happens! ๐ŸŽ†

After a short while, you can click over to your new Google Sheet, populated with all of your transaction data!

How we use Google Sheets to track our spending habits

We’ve setup categories to group our transactions, so that we can see how much we’re spending on different things at a high-level. For example, we group all restaurant expenses together into an “Eating Out” category, which allows us to see how much we spend eating out.

You want enough categories to differentiate items in a meaningful way, but not too many that you end up with too much granularity. The whole idea is to summarize transactions into something more manageable.

Each week my wife or I will jump into the Tiller Sheet and categorize any new transactions. It’s as simple as selecting the category from the drop-down menu in Transactions tab in the blank cell next to the transaction name:

Categorizing transactions in Google Sheets with Tiller

You can even use Tiller’s new Autocat tool to now automatically categorize transactions for you.

Creating custom reports with Tiller and Google Sheets

I’m going to share our solution for tracking our spending habits.

It allows us to understand how we’re spending our money and identify ways to reduce it.

I created a summary table in our Tiller Google Sheet, which shows our family spending by category. It takes the data we’ve categorized in the transactions tab, which is automatically updated by Tiller, and summarizes it.

The transactions are summarized by categories in the rows, and by months across the columns. Columns A and B contain checkboxes, which I use to control which spending categories to show in my charts.

Google Sheet with Tiller template

This table alone gives us more insight into our spending habits than anything the bank gives us. Every single transaction is included and categorized, by us not the bank.

You can create a table like this with the QUERY function, or using a Pivot Table.

In my case, I’ve used a QUERY function in cell C3 to retrieve, aggregate and pivot my transaction data:

=QUERY(QUERY(Transactions!A1:O,"select C, sum(D)*-1 group by C pivot K"),"offset 1",0)

Visualizing our spending habits in Google Sheets

I added the checkboxes in columns A and B, so there’s a way for my wife and I to choose categories to focus on.

The checkboxes can be individually checked or unchecked and they feed into other data tables that only show the data for the checked items.

Our mortgage, car lease and utility payments remain largely the same month-to-month. We know we have to pay them every month, so we don’t necessarily need to see them every time. (That’s not to say they’re not important, but trying to visualize all your categories at once will just clutter your charts to the point of being useless. )

However, seeing our discretionary spending — things like travel and eating out for example — helps us understand our spending habits and find ways to save more money in a healthy way.

We’re currently using two charts to track our spending habits:

Chart 1: Current monthly spend vs. Average monthly spend

The first is a monthly breakdown by category, showing actual spend this month (blue) against the average amount we spend in this category each month (red):

Google Sheets Tiller Monthly spending chart

(Chart shows fictional data.)

Chart 2: Discretionary Spend by Month

The second is a look at our discretionary spending over the past few months, so we can see how selected categories are trending (chart shows fictional data):

Google Sheets Tiller Monthly discretionary spending chart

The combination of the monthly category breakdown table and these two simple charts gives us tremendous insight into our spending habits.

Knowing how we’re spending our money gives us tremendous peace of mind.

It’s helping us to minimize our unnecessary spending and maximize our saving.


Tiller homepage

10 techniques to use when building budget templates in Google Sheets

A guide to the super useful QUERY function

A Beginnerโ€™s Guide to Pivot Tables in Google Sheets

How to use checkboxes in Google Sheets

Note: I’m not a financial expert and this post does not provide financial advice. It simply shows some techniques for working with and presenting data in Google Sheets.

Pivot Tables 101: A Beginner’s Guide

How to use Google Sheets A Beginner’s Guide to Pivot Tables in Google Sheets

If you use Google Sheets, or any spreadsheet application for that matter, but don’t use Pivot Tables, then you’re missing out on one of the most powerful and useful features available.

This tutorial will (attempt to) demystify Pivot Tables and give you the confidence to start using them in your own work.


  1. An Introduction to Pivot Tables
    • What are Pivot Tables?
    • Why use Pivot Tables?
    • How to create your first Pivot Table
    • Let Google build them for you

  2. Pivot Tables: Fundamentals
    • Rows, columns and values
    • Totals
    • Sorting

  3. Pivot Tables: Tips and Tricks
    • Multiple value fields
    • Changing aggregation types
    • Adding filters
    • Multiple row fields
    • Copying Pivot Tables

  4. Pivot Tables: Next steps

1. An Introduction to Pivot Tables

What are Pivot Tables?

Let’s see a super simple example, to demonstrate how Pivot Tables work. Consider this dataset:

Dataset for pivot tables

You want to summarize the data and answer questions like: how many apartments are there in the dataset? What’s the total cost of all the apartments?

Now, this would be easy to do with formulas, using a COUNTIF and a SUMIF, but if you change our mind and now want to summarize “Condo” you have to modify all your formulas, which is a pain.

Enter the Pivot Table:

Basic pivot table in Google Sheets

This took me eight mouse clicks and I didn’t have to write a single formula (in a few paragraphs I’ll show you those exact 8 clicks so you can build your own version).
Continue reading Pivot Tables 101: A Beginner’s Guide

Mapping data with Pivot Tables in Google Sheets…yes, really! ๐ŸŒŽ

Let me show you a unique use case for pivot tables – building maps!

Pivot Table Map of Washington DC

Can you guess which city this is?

It’s Washington D.C. and it’s also a pivot table in Google Sheets. The image on the left is the map built with a pivot table. The image on the right is a screenshot of Washington D.C. from Google maps.

Look closely and you might just be able to see the Google Sheet row and column headings around the map.

Wait, what?
Continue reading Mapping data with Pivot Tables in Google Sheets…yes, really! ๐ŸŒŽ

Format your Google Sheet tables so they look good GREAT

A collection of formatting tips for tables in your Google Sheets.

Google Sheets formatting for tables

Formatting Tables

Let’s start with a simple table, completely devoid of any formatting:

Table no format

Header rows

Go for bold, center-aligned and wrap the text, so it all shows.

Google Sheets formatting column headings
Continue reading Format your Google Sheet tables so they look good GREAT