DEV Community: moses odhiambo

INTRODUCTION TO MS EXCEL FOR DATA ANALYTICS

moses odhiambo — Sun, 25 Jan 2026 05:15:20 +0000

#What is Microsoft Excel?

Microsoft Excel is a spreadsheet application used to store, organize, clean, and analyze data. It allows users to work with data in rows and columns and perform calculations, summaries, and simple analysis without programming.

In data analytics, Excel is often the first tool beginners learn because it is visual, easy to understand, and widely used in workplaces.

##Understanding the Excel Interface

When you open Excel, you will see:

_Workbook _– the Excel file
Worksheet – individual sheets inside a workbook
Rows – horizontal (numbers: 1, 2, 3…)
Columns – vertical (letters: A, B, C…)
Cells – intersection of a row and column (e.g., A1)

Each cell can hold:

1.Text
2.Numbers
3.Dates
4.Formulas

###Types of Data in Excel

Excel commonly works with the following data types:

_- Text (Names, Categories, Locations)

Numbers (Sales, Age, Quantity)
Dates & Time
Boolean values (TRUE/FALSE)_

Understanding data types is important because formulas only work correctly when data is properly formatted.

####Basic Data Entry and Formatting

Data Entry

Click on a cell and type your data
Press Enter to move down or Tab to move right

Basic Formatting

Formatting helps make data easier to read:
Bold headers
Adjust column width
Apply number formats (currency, percentage, date)
Add borders to tables

N/B: Good formatting improves clarity, not analysis but clarity matters.

#####Sorting and Filtering Data

Sorting

Sorting helps organize data:

Ascending (A–Z, smallest to largest)
Descending (Z–A, largest to smallest)
Example: Sorting sales from highest to lowest.

Filtering

Filtering allows you to view specific records without deleting others. Example:

Show only sales from Nairobi/Mombasa
Show only products with sales above 10,000
Sorting and filtering are essential for exploring data quickly.

######Basic Excel Formulas for Data Analysis
Take note Formulas always start with an equals sign (=)

Common beginner formulas:

=SUM() – Adds values
=AVERAGE() – Calculates mean
=COUNT() – Counts numeric values
=MAX() – Finds the highest value
=MIN() – Finds the lowest value

Examples:

=SUM(B2:B10)

This formulas turn raw data into useful insights...

#######Introduction to Data Cleaning in Excel

Before analysis, data must be clean.
Common data cleaning tasks:
Removing duplicate values
Fixing spelling inconsistencies
Handling empty cells
Trimming extra spaces
Ensuring consistent data formats
Clean data leads to accurate analysis

########Simple Data Analysis Using Excel

With clean data, Excel can be used to:
Calculate totals and averages
Compare categories
Identify trends
Answer basic questions such as:
Which product sold the most?
What is the average monthly revenue?
Which region performs better?
This is the foundation of data analytics.

#########Why Excel is Important for Data Analytics Beginners

Excel is important because:

It requires no coding
It is used in almost every industry
It helps understand data concepts visually
It prepares learners for advanced tools like SQL, Python, and Power BI

N/B: Many professional data analysts still use Excel daily.

##########Summary

What Excel is and how it is used in data analytics
How to navigate the Excel interface
Basic data entry, formatting, sorting, and filtering
Simple formulas for analysis
The importance of clean data
Excel is the starting point of a data analytics journey.

Don't Be Afraid of Git: A Beginner's Guide to Saving and Sharing

moses odhiambo — Sun, 18 Jan 2026 02:35:42 +0000

#Don't Be Afraid of Git

When I first heard about Git, I thought it was something only senior developers could use.

Turns out, Git is actually very simple. We just make it sound complicated.

This article explains Git in the easiest way possible.

No big words. No stress. Just what Git does and how you can use it.

##What is Git?

Git is a tool that remembers your code.

Every time you change something, Git can:

Save it
Remember what changed
Let you go back if you make a mistake

If you’ve ever renamed files like:

final.js → final-final.js → final-final-please-work.js

…then Git is exactly what you need.

###What Is Version Control?
Version control just means keeping a history of your work.

Think of it like WhatsApp:

You can scroll back and see old messages
You know what was sent
You can restore something if needed

Git does the same thing, but for code.

If your project breaks today, you can go back to yesterday when it worked.

####Git vs GitHub

This confused me at first too.

Git lives on your computer
GitHub lives on the internet

Git is the tool.

GitHub is where you store your projects online.

Think of it like this:

Git = your notebook at home
GitHub = cloud storage for your notebook

*#####Starting a Git Project*

You don’t need anything fancy.

All you need:

A folder
Some files
Some code

Inside that folder, run:

git --version

Hold on, yes let take a minute, before Before we jump right onto it, let’s make sure Git is already installed on your computer.

Alright once you have installed Git in your Machine, proceed by opening Git once its open run this:

git --version

"If" and yes I have said "if" Git is installed, you’ll see something like:

git version 2.52.0.windows.1

That means Git is ready to use.

If you see an error or nothing shows up, it just means Git is not installed yet.

You can install it and then come back to this guide.
This small step helps avoid confusion later.

######Configure Git (Tell Git Who You Are)

Before Git starts saving your work, it wants to know your name and email.
please don't be scared.
Git just wants to label your saved changes so it knows who made them.

Step 1: Set Your Name

git config --global user.name "Your Name"

Example:

git config --global user.name "Moses Odhiambo"

Step 2: Set Your Email

 git config --global user.name "your email@example.com"

Please note that you must use the same e mail you use on GitHub.

For your information:

What Does This Do?

This does not:

Create an account
Send emails
Share your private info

It simply helps Git say: “This change was made by Moses.”

Every time you commit code, Git uses this information.

#######Check Your Configuration

So now here basically helps us check that every details is set correctly , to confirm this run:

git config --list

Now after running it you are supposed to see your name and email in the list, like as follows:

 git config --list
diff.astextplain.textconv=astextplain
filter.lfs.clean=git-lfs clean -- %f
filter.lfs.smudge=git-lfs smudge -- %f
filter.lfs.process=git-lfs filter-process
filter.lfs.required=true
http.sslbackend=schannel
core.autocrlf=true
core.fscache=true
core.symlinks=false
pull.rebase=false
credential.helper=manager
credential.https://dev.azure.com.usehttppath=true
init.defaultbranch=master
core.editor="C:\Users\Hp\AppData\Local\Programs\Microsoft VS Code\bin\code" --wa
it
user.name=odhiambomoses67@gmail.com
user.email=odhiambomoses67@gmail.com
core.repositoryformatversion=0
core.filemode=false
core.bare=false
core.logallrefupdates=true
core.symlinks=false
core.ignorecase=true
:

Why This Step Matters

If you skip this step:

Git may refuse to save your work
Or it may save commits without your name

Configuring Git once saves you trouble later.
You only need to do this one time.

Why Do We Use --global?
Yes just like you, I asked myself why do we need to use --global?.

well when you see this command:

git config --global user.name "Your Name"

The word --global just means: “Use this name and email for all my Git projects on this computer.” Imagine just like.

What Happens When You Use --global

Git remembers your name once
Git remembers your email once
Every project you create will use this information
You don’t have to repeat it for every new folder or project.

What If You Don’t Use --global?

If you remove --global, Git will:

Ask you to set your name and email again
Do it for each project separately
That’s extra work, especially when you’re just starting out.
When Would You Not Use --global?

Sometimes people:

Use different emails for work and personal projects
Contribute to company projects
In that case, they may set the name and email only for that project.
But for beginners?
Always use --global.
It keeps things simple.
Simple Way to Remember
--global = everywhere on this computer
No --global = only this one project

########What Is a Git Agent? (SSH Agent )

You thought An agent is the one from your M-pesa, bank Or that Friend of yours who sales land, then your wrong.
let me tell you something maina, An Agent is just a helper period.

In Git, the most common one is the SSH agent.

Think of the SSH agent like this:

“A trusted guard that remembers your key so GitHub knows it’s really you.”

Why Do We Need an Agent?

When you push code to GitHub, GitHub wants to be sure: It’s really you not someone else pretending.

The SSH agent helps by:

Holding your SSH key in memory
Letting Git talk to GitHub securely
Preventing you from typing passwords every time

What the SSH Agent Actually Does

Once it’s running:

Git uses it automatically
You don’t see it working
You don’t interact with it every time
It just quietly helps in the background.

Do Beginners Need to Worry About This?

Not much and that’s okay.

If you:

Installed Git normally
Use GitHub
Push and pull code successfully
Then the agent is already doing its job.
Most beginners don’t notice it until:
They set up SSH keys
Or Git asks for authentication

Simple Way to Think About It

Git → saves your code
GitHub → stores it online
SSH Agent → proves you are allowed to send it

Bottom Line

You don’t need to master agents to use Git.
Just know this: The agent is a helper that keeps Git and GitHub talking safely.

########GitHub Settings for Beginners

So now, before you can push code online, you need to set up GitHub and connect it to your computer. Clam down it’s easier than it sounds, allow me your captain to take you through, kindly fasten your fasten belt.

Step 1: Create a GitHub Account

Go to GitHub.com
Click Sign Up
Enter your username, email, and password
Verify your email

N/B : Use the same email you configured in Git (git config --global user.email).

Step 2: Create a New Repository

Click the + icon in the top-right corner → New Repository
Name your repository (e.g., my-first-git-project)
Choose Public or Private
Don’t check Initialize with a README if you already have a local project
Click Create Repository
This will give you the URL to connect your local project.

Step 3: Set Up SSH (Optional but Recommended)

SSH helps you connect your computer to GitHub securely without typing your password every time.

Open your terminal
Check for existing SSH keys:

ls -al ~/.ssh

If no key exists, create one:

ssh-keygen -t ed25519 -C "youremail@example.com"

Press Enter to accept defaults.
Start the SSH agent:

eval "$(ssh-agent -s)"

Add your SSH key to the agent:

ssh-add ~/.ssh/id_ed25519


- *Copy the key to GitHub:*

cat ~/.ssh/id_ed25519.pub

*Paste it in GitHub → Settings → SSH and GPG keys → New SSH key*


***Step 4: Link Your Local Project to GitHub***

*- In your project folder:*

git remote add origin git@github.com:username/repo.git

*Replace username and repo with your GitHub username and repository name.*

***Step 5: Push Your First Commit***

git push -u origin main


*Now your local project is online on GitHub, ready to share or collaborate.*

**#########Installing PostgreSQL on Windows (Step by Step)**

*Step 1: Go to the PostgreSQL website*

- Open your browser and go to:
- https://www.postgresql.org
- On the homepage:
- Click Download
- Choose Windows
Screenshot here: PostgreSQL homepage with “Download” highlighted

***Step 2: Download the installer***

- Click Download the installer
- You’ll be redirected to EnterpriseDB
- Download the latest version (recommended)

*The file will look like:*

postgresql-16.x-windows-x64.exe

Screenshot here: Download page showing Windows installer

***Step 3: Run the installer***

- Double-click the downloaded .exe file
- Click Yes if Windows asks for permission
- You’ll see the PostgreSQL Setup Wizard.

 Screenshot here: PostgreSQL Setup Wizard welcome screen

***Step 4: Choose installation directory***

- Click Next to keep the default path:

C:\Program Files\PostgreSQL\16


- Beginners should not change this.

 Screenshot here: Installation directory screen

***Step 5: Select components to install***

*Make sure ALL are checked:*

-  PostgreSQL Server
-  pgAdmin 4
-  Stack Builder
-  Command Line Tools

- Click Next

 Screenshot here: Components checklist

***Step 6: Set database data directory***

- Leave it as default:

C:\Program Files\PostgreSQL\16\data


- Click Next.

 Screenshot here: Data directory screen

***Step 7: Set the PostgreSQL password (VERY IMPORTANT)***

- This password is for the postgres admin user.
- Choose a password you will remember
- Do NOT leave it blank
- Example:

postgres123


- Click Next.
Screenshot here: Password setup screen


***Step 8: Choose the port number***

- Leave it as default:

5432


- This is the standard PostgreSQL port.
- Click Next.

 Screenshot here: Port configuration screen

*Step 9: Locale settings*

- Leave it as:

Default locale


- Click Next.

Screenshot here: Locale selection screen


***Step 10: Start installation***

- Click Next → Install
- Wait for installation to complete (2–5 minutes).

Screenshot here: Installation progress bar

***Step 11: Finish installation***

Uncheck Stack Builder (optional)

- Click Finish
- PostgreSQL is now installed 

Screenshot here: Installation complete screen


***Step 12: Confirm PostgreSQL is working***

- Option 1: Using pgAdmin
- Open pgAdmin 4
- Enter the password you created
- Expand Servers → PostgreSQL

 Screenshot here: pgAdmin dashboard


- Option 2: Using Command Line
- Open Command Prompt and run:

psql --version


- You should see something like:

psql (PostgreSQL) 16.1



- This confirms PostgreSQL is installed correctly.



**##########Connecting PostgreSQL to DBeaver (Step by Step)**

So now this part explains how to see and work with your PostgreSQL database visually using DBeaver.

***What is DBeaver?***

*DBeaver is a window you use to:*

- See your databases
- See tables and data
- Write SQL without fear
- PostgreSQL is the brain
- DBeaver is the face you talk to.

***Step 1: Download and install DBeaver***

- Go to: https://dbeaver.io
- Click Download
- Choose DBeaver Community (Free)
- Download the Windows installer
- Install using Next → Next → Finish

 Screenshot here: DBeaver download page

***Step 2: Open DBeaver***

- Launch DBeaver
- You’ll see a welcome screen or empty workspace

 Screenshot here: DBeaver home screen

***Step 3: Create a new database connection***

- Click New Database Connection (or the plug 🔌 icon)

Screenshot here: “New Database Connection” button highlighted

***Step 4: Select PostgreSQL***

- From the list, choose PostgreSQL
- Click Next

Screenshot here: PostgreSQL selected from database list

*Step 5: Enter PostgreSQL connection details*

*Fill the fields like this:*


| **Field**  | **Value**
|------------|-----------
|Host        | localhost
|Port        | 5432
|Database    | postgres
|Username    | postgres
|Password    |(the password you set during installation)

 Screenshot here: Connection settings filled in

***Step 6: Download PostgreSQL driver***

*The first time:*

- DBeaver will ask to download the PostgreSQL driver
- Click Download

 Screenshot here: Driver download popup


***Step 7: Test the connection***

- Click Test Connection
- If successful, click Finish
- If it fails:
- Check password
- Ensure PostgreSQL service is running

 Screenshot here: “Connected successfully” message


*Step 8: Explore your PostgreSQL database*

*On the left panel:*

Servers
└── PostgreSQL
└── Databases
└── postgres


- You can now:
- View schemas
- Create tables
- Run SQL queries

 Screenshot here: Database tree expanded

***Step 9: Run your first SQL query***

- Right-click the database
- Click SQL Editor → New SQL Script
- Type:

SELECT version();


- Click Run ▶

- You’ll see PostgreSQL version details.

Screenshot here: SQL editor with query results

**What just happened **

- PostgreSQL is running in the background
- DBeaver connects to it using credentials
- You are now talking to the database safely


***How this fits with Git & GitHub***

- Best practice:
- SQL files are saved in a project folder
- That folder is tracked by Git
- Changes are pushed to GitHub
- Example:

project/
├── sql/
│ └── create_tables.sql
├── README.md
└── .git/


**###########Using PostgreSQL with Visual Studio Code (VS Code)**

This part shows how VS Code helps you write SQL, manage files, and work with Git all in one place.


***What is VS Code***

Visual Studio Code is like a smart notebook for developers.

*You can:*

- Write SQL
- Write Python
- Track changes with Git
- Open your whole project in one window
- PostgreSQL stores data
- VS Code stores your work files

***Step 1: Install Visual Studio Code***

- Go to:https://code.visualstudio.com
- Click Download for Windows
- Install using default settings

 Screenshot here: VS Code download page

***Step 2: Open your project folder***

- Create a folder on your PC:

postgres-project


- Open VS Code
- Click File → Open Folder
- Select postgres-project

 Screenshot here: Open folder in VS Code


***Step 3: Create SQL files***

- Inside VS Code:
- Right-click → New File
- Name it:

create_tables.sql

*Add this code:*

CREATE TABLE users (
id SERIAL PRIMARY KEY,
name TEXT,
email TEXT
);


Screenshot here: SQL file opened in VS Code


***Step 4: Install PostgreSQL extension in VS Code*
**

- Click Extensions (left sidebar)
- Search: PostgreSQL
- Install PostgreSQL by Chris Kolkman or SQLTools

 Screenshot here: PostgreSQL extension installed


***Step 5: Connect PostgreSQL inside VS Code***

- Using SQLTools:
- Open Command Palette (Ctrl + Shift + P)
- Select SQLTools: Add New Connection
- Choose PostgreSQL
- Enter:
- Server: localhost
- Port: 5432
- Database: my_app_db
- Username: my_user
- Password: your password

Screenshot here: PostgreSQL connection setup in VS Code


***Step 6: Run SQL from VS Code***

- Open your .sql file
- Select the SQL
- Right-click → Run Query
- Results appear in the output panel.
- You’re now using PostgreSQL from VS Code.

_*Why developers love this setup*_

- SQL files are saved
- Git tracks changes
- You can undo mistakes
- Everything is organized

*How Git fits here*

Your project folder now looks like this:

postgres-project/
├── sql/
│ └── create_tables.sql
├── README.md
└── .git/


_Each change you make:_

git add .
git commit -m "Create users table"
git push

**_Beginner mistake to avoid_**

-  Writing SQL only inside DBeaver
-  Always save SQL files in VS Code and commit them

**Using PostgreSQL with Python**

_**What Python does here**_

Python talks to PostgreSQL and says:

- “Save this data”
- “Get this data”
- PostgreSQL listens. Python works.

_**Step 1: Install Python
**_

- Download from https://python.org
- During install, check Add Python to PATH

 Screenshot here: Python installer with PATH checked

**_Step 2: Install PostgreSQL driver_**

_Open Command Prompt and run:_

pip install psycopg2-binary


_This lets Python talk to PostgreSQL._

**_Step 3: Simple Python connection_**

_Create a file:_

app.py

_Add this code:_

import psycopg2

conn = psycopg2.connect(
host="localhost",
database="my_app_db",
user="my_user",
password="mypassword"
)

print("Connected to PostgreSQL")


_**Run:**_

python app.py




__If you see Connected to PostgreSQL, it worked.
_

**#############Connecting PostgreSQL to Power BI**
Power BI is a tool to visualize your data charts, tables, dashboards without touching SQL every time.


_**Step 1: Open Power BI Desktop**_

- Download from Power BI Desktop
- Install and launch it

Screenshot here: Power BI Desktop home screen


_**Step 2: Get Data from PostgreSQL**_

- Click Home → Get Data → More → Database → PostgreSQL

- Enter:
Server: _localhost_
Database: _my_app_db_

- Click OK

Screenshot here: PostgreSQL connection popup

_**Step 3: Enter credentials**_

- Username: _my_user_
- Password: _mypassword_
- Click Connect


_**Step 4: Select tables**_

- Power BI shows a list of tables from your database
- Select the table(s) you want
- Click Load

Screenshot here: Loaded tables in Power BI


_**Step 5: Build visuals**_

- Drag fields onto the canvas
- Create charts, tables, or dashboards
- Use filters to explore your data

N/B: Power BI does not change the database; it only reads the data.

_**Step 6: Refresh your data**_

- If PostgreSQL data changes, click Refresh in Power BI
- Your visuals update automatically


_**Why this matters for beginners**_

- You can analyze real data quickly.
- Works with Git projects: save _.pbix_ files in your project folder.
- Combine with Python & SQL for full workflow.

**##############Connecting PostgreSQL to Excel**

- Excel helps you view and analyze data from PostgreSQL using tables, filters, and charts.
- PostgreSQL stores the data.
- Excel shows the data.

_**Step 1: Open Excel**_

- Open Microsoft Excel
- Click Data (top menu)

 Screenshot here: Excel Data tab


_**Step 2: Get data from PostgreSQL**_

1. Click Get Data
2. Choose From Database
3. Select From PostgreSQL Database

Screenshot here: Get Data → PostgreSQL option



_**Step 3: Enter database details**_

Fill in:

- Server: _localhost_
- Database: _my_app_db_
- Click OK

Screenshot here: PostgreSQL connection window

_**Step 4: Enter login details**_

- Username: _**my_user**_
- Password: _**mypassword**_
- Click Connect

_**Step 5: Select tables**_

- Excel shows available tables
- Select the table you want
- Click Load
- Your PostgreSQL data appears in Excel.

Screenshot here: Table loaded in Excel


_**Step 6: Refresh data**_


- If data changes in PostgreSQL:
- Click Refresh
- Excel updates automatically

Screenshot here: Refresh button

_**Why beginners love this:**_

- No SQL needed after setup
- Easy charts & filters
- Works well with Power BI later

_**Important beginner tip**_

1. Don’t edit important data directly in Excel
2. Use Excel mainly for reading and analysis


**Final Words**

So folks, that’s all we had to learn for today.
May the forces of Data, the glory of Science, and the blessings of Analytics and Engineering always be on your side.

_**Remember this:**_

1. Make it easy
2. Don’t rush

- The golden rule: don’t panic, don’t tense
- Every expert you admire once started exactly where you are now.
- Slow steps beat fast mistakes.
- Stay calm, stay curious, and keep building.
- See you in the next one