Forem: Ibrahim Khalif

HOW TO CONNECT POWER BI TO SQL DATABASE

Ibrahim Khalif — Sun, 08 Mar 2026 19:45:44 +0000

Power BI is one of the most powerful tools for turning raw data into interactive dashboards and reports.
Connecting it to a SQL database (SQL Server, Azure SQL Database, or similar) is the most common and efficient way to analyze large datasets in real time.

Requirements

Power BI Desktop (free download from Microsoft)
Access to a SQL database (on-premises SQL Server, Azure SQL, or SQL Managed Instance)
Server name, database name, and login credentials (Windows authentication or SQL Server authentication)
Appropriate permissions on the database

Step 1: Open Power BI Desktop and Select Get Data

Launch Power BI Desktop. On the Home tab in the ribbon, click the Get data dropdown and choose SQL Server (it appears directly in the common data sources list).

Step 2: Enter Server and Database Details

Server: Enter your server name (e.g., localhost, myserver\instance, or -Azure SQL like myserver.database.windows.net)
Database (optional but recommended): Type the exact database name
Data Connectivity mode: Choose Import (recommended for most users) or DirectQuery (for live data without importing)

click ok

Step 3: Provide Authentication Credentials

Power BI will prompt you to sign in.
-For Windows Authentication (most common on-premises): Select Use my current credentials
-For SQL Server Authentication: Choose Use alternate credentials and enter username/password
-For Azure SQL: Use Microsoft account or SQL authentication.

click connect

Step 4: Select Tables in the Navigator

-The Navigator window appears, showing all tables, views, and stored procedures in your database.
-Check the boxes for the tables you want
-Use the preview pane on the right to see sample data
(Optional) Click Transform Data to clean data in Power Query first

When ready, click Load.

Step 5: Build Your First Report

Once loaded, switch to Report view. You’ll see your tables in the Fields pane on the right.
Drag fields onto the canvas to create charts, tables, and visuals instantly.

Power BI Data Modeling and Schema Design

Ibrahim Khalif — Sun, 01 Feb 2026 17:54:07 +0000

Overview of Power BI

Power BI is a business analytics tool by Microsoft used to:

Analyze data
Create interactive reports
Build dashboards
Share insights visually

components of Power BI

Power BI Desktop
Used to import data, clean data, and build reports
Installed on your computer
Main tool for beginners
Power BI Service (Online)
Used to publish and share reports
Runs in a web browser
Power BI Mobile
View dashboards on mobile devices

Installing Power BI Desktop

Go to Microsoft Store or official Power BI website
Search Power BI Desktop
Download and install
Open the application

Data Sources in Power BI

Power BI can connect to many data sources such as:
Excel
CSV files
SQL Server
Web data
SharePoint
Google Sheets

Power BI Workflow

The Power BI workflow answers one big question:
How do I turn raw data into insights people can understand and trust?
The workflow has 6 main stages:

Data → Cleaning → Modeling → Calculations → Visualization → Sharing

Get Data – “Where is my data coming from?”

What this step means
This is where you connect Power BI to your data source.
Power BI does NOT store data like Excel.
It connects, loads, and refreshes data.
Common data sources

Excel files
CSV files
Databases
Web data
SharePoint

NOTE: What beginners often miss
Thinking Power BI is only for Excel
Loading messy data without checking it
Loading everything instead of only what is needed

Transform Data (Power Query) – “Is my data clean?”

This is THE MOST IMPORTANT STEP for beginners.
What Power Query does
Power Query is where you:

Clean data
Fix errors
Prepare data for analysis
Typical cleaning tasks
Remove blank rows
Remove duplicates

Fix data types (text vs number vs date)

Rename columns
Handle missing values
Trim extra spaces

Example
If you have:
Discount = "20%" (text)`

Power BI cannot calculate with it.
You must convert it to:

0.2 (number)
Beginner mistake

Skipping Power Query
Doing cleaning in visuals instead of Power Query
Leaving columns as text

Golden rule
If your data is wrong, your visuals will lie.

Load Data – “Freeze the clean version”
When you click Close & Apply:

Power BI loads the cleaned data
This becomes the official dataset

Data Modeling – “How do tables talk to each other?”
This is where Power BI becomes powerful.
What modeling means

It defines:

Relationships between tables
How filters flow
How calculations behave

Example
You may have:
1.Sales table
2.Products table
3.Customers table
You connect them using keys like:
ProductID CustomerID
Relationship types

One-to-Many (MOST COMMON)
Many-to-Many (advanced)
One-to-One (rare)

Beginner mistake
No relationships
Wrong direction of relationship
Using one big flat table when a model is better

DAX Calculations – “What questions am I asking?”
DAX is NOT Excel formulas.

It is about context.
Two types of DAX
1.Calculated Columns
- Calculated row by row
- Stored in the table
Example:
Profit = Sales[Revenue] - Sales[Cost]
2.Measures (VERY IMPORTANT)
- Calculated on demand
- Change with filters
Example:
Total Sales = SUM(Sales[Revenue])
Why measures are preferred
- Faster
- Dynamic
- Used in visuals

Beginner mistake

Using calculated columns for everything
Not understanding filter context
Hardcoding numbers

Build Visuals – “How do I tell the story?”
This is where insights become visible.
What visuals do

Show patterns
Compare values
Highlight trends
Support decisions

Common visuals and their purpose
Visual When to use

Bar/Column- Compare categories
Line- Trends over time
Pie- Share/percentage
Table- Details number
Scatter- Relationships

Beginner mistake
Too many visuals
No titles
Wrong visual type
Decorative instead of informative

Report Design – “Can someone understand this in 5 seconds?”

Design matters.
Good report design
Clear titles
Logical layout
Consistent colors
Important KPIs at the top

Publish & Share – “Who needs to see this?”
Publishing does

Uploads report to Power BI Service
Enables sharing
Allows refresh

Beginner mistake
Publishing without checking data
No explanation for users

The FULL Workflow Summary (Mental Map)

Raw Data ↓ Power Query (Clean & Fix) ↓ Data Model (Relationships) ↓ DAX (Answer Questions) ↓ Visuals (Tell Story) ↓ Publish (Share Insights)

Introduction to MS Excel for Data Analytics

Ibrahim Khalif — Sun, 25 Jan 2026 12:32:10 +0000

Excel is a spreadsheet program developed by Microsoft. It allows you to:

Collect data
Organize data
Analyze and calculate numbers
Visualize data using tables and charts

It is widely used in:

Personal finance (budgets, expenses)
Business (sales reports, HR reports, inventory)
Education (student marks, attendance)
Data analysis and dashboards

The Excel Interface

When you open Excel, you see:

Ribbon
The big toolbar at the top.
Contains tabs like Home, Insert, Page Layout, Formulas, Data, Review, View.
Each tab has groups (e.g., Font, Alignment, Number under Home).

Quick Access Toolbar

Small toolbar at top left.
Common icons: Save, Undo, Redo.
You can add your favorite commands.

Formula Bar

Located above the grid, under the Ribbon.
Shows what is in the active cell (text, number, or formula).
You can click inside it to edit cell content.

Columns

Vertical groups of cells.
Labeled A, B, C, ... at the top.

Rows

Horizontal groups of cells.
Labeled 1, 2, 3, ... at the left.

Cell

Single box at the intersection of a row and a column.
Address like A1, B2, D10.

Range

A group of cells.
Written like A1:C3 (from A1 to C3).
Can be: Entire column: A:A Entire row: 1:1 Multiple columns: A:D Multiple rows: 5:10

How to save for the first time (Save As):

Click File in the top left.
Click Save As.
Choose a folder (e.g., Desktop, Documents).
Type a file name (e.g., My First Workbook).
Ensure the file type is Excel Workbook (*.xlsx).
Click Save. Quick save later:

Press Ctrl + S anytime to save changes.

How to open an existing workbook:

Open Excel.
Click File > Open.
Browse to the folder where the file is saved.
Click the file and click Open.

Practice using Ctrl + S often to avoid losing work.

Types of Data You Can Enter

Text (labels) Example: “Nairobi”, “Salary”, “Employee Name”
Numbers Example: 400, 89.5, 12000
Dates Example: 01/06/2025, 3-Jun-2025
Times Example: 10:30 AM, 14:45
Formulas
Must start with = Example: =A1+B1, =SUM(B2:B10)

Navigating with Keyboard and Mouse

Keyboard:

Arrow keys → move one cell at a time.
Tab → move one cell to the right.
Shift + Tab → move one cell to the left.
Enter → move down one cell.
Shift + Enter → move up one cell.
Ctrl + Arrow → jump to the edge of data (end of a continuous block).
Ctrl + Home → go to A1.
Ctrl + End → go to the last used cell.
Ctrl + S → save.

Mouse:

Click a cell to select it.
Click and drag to select multiple cells (range).
Scroll with mouse wheel to move up/down.

Formatting & Cleaning Data

This section covers:

Text formatting (Bold, Italic, Colors)
Alignment (horizontal, vertical, Wrap Text, Merge & Center)
Number formats (Number, Currency, Percentage, Date, Time)
Borders and Fill Colors
Conditional Formatting
Removing duplicates

Text Formatting

Steps:

Select the cells (e.g., A1:D1).
Go to the Home tab.
In the Font group:

-  Click B for Bold.
-  Click I for Italic.
-  Click U for Underline.
-  Change font type (e.g., Calibri, Arial).
-  Change font size (e.g., 11 → 14).
-  Change font color.

Alignment determines where content sits inside the cell. Steps:

Select the cells.
Home tab > Alignment group.
Options:
- Horizontal: Align Left, Center, Align Right.
- Vertical: Top, Middle, Bottom.
- Wrap Text: Shows long text on multiple lines inside the same cell.
- Merge & Center: Combines multiple cells into one and centers the text.

Examples:

Wrap Text:
- A2 contains “Total Sales for January and February 2025”.
- Select A2 → click Wrap Text → it appears on two or more lines.
Merge & Center:
- You have a report title above a table from A2:D10.
- Type “Sales Report 2025” in A1.
- Select A1:D1 → click Merge

Number Formatting

Number formats change how numbers look without changing their actual value. Common formats:

General (default)
Number (can show decimal places)
Currency (shows a currency symbol)
Accounting
Percentage (%)
Date
Time

Steps:

Select the cells with numbers.
Home tab > Number group.
Use the dropdown to choose Number, Currency, Percentage, Short Date, etc. Additional options: • Increase/Decrease Decimal buttons to control decimal places.

Removing Duplicates

Duplicate rows can cause incorrect totals or confusion. Steps:

Select your dataset (e.g., A1:D200).
Go to Data tab > Remove Duplicates.
Ensure you have “My data has headers” ticked if the first row has column titles.
Select the columns that define a duplicate (e.g., Name and Email).
Click OK.
Excel shows a message with how many duplicate rows were removed.

Excel Functions Cheat Sheet

Basic Functions

=SUM(A1:A10)
What it does: Adds all numbers in the selected range.
Where to use:

Total sales or revenue
Total marks or scores
Total expenses

=AVERAGE(A1:A10)
What it does: Calculates the mean (average) value.
Where to use:

Average salary
Average student score
Average monthly sales

=COUNT(A1:A10)
What it does: Counts cells that contain numbers only.
Where to use:

Counting number of entries
Counting completed numeric records

=COUNTA(A1:A10)
What it does: Counts all non-empty cells (text, numbers, symbols).
Where to use:

Counting filled records
Checking how many employees or items are listed

=MAX(A1:A10)
What it does: Returns the highest value in a range.
Where to use:

Highest sales
Top score
Maximum salary

=MIN(A1:A10)
What it does: Returns the lowest value in a range.
Where to use:

Lowest sales
Minimum score
Cheapest price

Lookup & Reference Functions
VLOOKUP
What it does:
Searches for a value in the first column of a table
Returns a value from another column in the same row

Where to use:

Getting employee names using employee ID
Getting product prices using product code

Limitation:

Lookup value must be in the first column
Breaks if columns are moved

HLOOKUP (Horizontal Lookup)
What it does:

Searches for a value in the first row
Returns a value from a row below Where to use: When data is arranged horizontally (months in rows)

INDEX
What it does:
Returns a value from a specific row and column in a range
Where to use:
When you know the exact position of data

XLOOKUP (Recommended)
What it does:

Searches a value in one column
Returns a matching value from another column Where to use:
- Modern replacement for VLOOKUP and HLOOKUP
- Flexible and more reliable Advantages:
- No need for column numbers
- Can lookup left or right
- Does not break when columns move

Conditional Functions
SUMIF
What it does:

Adds values in a range only if a condition is met Where to use:
Total sales above a target
Total marks greater than a pass score

SUMIFS (Multiple Conditions)
What it does:
Adds values that meet multiple conditions
Where to use:
Total sales y department and region
Total salary for a specific role and grade

COUNTIF
What it does:

Counts cells that meet one condition Where to use:
Counting passed students
Counting completed tasks

COUNTIFS (Multiple Conditions)
What it does:

Counts cells that meet multiple conditions Where to use:
Employees who met targets
Students who passed and scored above average

AVERAGEIF
What it does:

Calculates average for values that meet a condition Where to use:
Average salary above a threshold
Average sales for top-performing products

Text Functions
CONCAT / CONCATENATE
What it does:

Joins text from multiple cells into one Where to use:
Combine first name and last name
Create full names or descriptions

MID
What it does:

Extracts text from the middle of a string Where to use:
Extract codes or names inside a text string

UPPER
What it does:

Converts text to uppercase Where to use:
Standardize names or codes

LOWER
What it does:

Converts text to lowercase Where to use:
Clean email addresses

How to create Pivot Tables
steps

Go to the insert bar

Click Pivot table and choose new work sheet

Pivot table will be created

To insert pivot chart you use the same process of pivot table but you now choose pivot chart

Begginer friendly on git bash commands and git hub

Ibrahim Khalif — Sun, 18 Jan 2026 08:36:41 +0000

How to download GitBash on your computer.

-Visit Git Bash
-Download the Windows installer
-Run the installer with these recommended settings:
    -Select "Use Git from Git Bash only "
    -Choose "Use the OpenSSL library"
    - Select "Checkout Windows-style, commit Unix-style line endings"
    -Choose "Use MinTTY"
    -Leave other options as default

For Mac Users:

Install Homebrew (if not installed):

/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"

Install Git:

brew install git

Verify:

git --version

How to push codes on git bash

When one whant's to check the version he/she is using

git --version

When you need help

git help

If you want to create a repository we use th command,

git init

while for existing repository we use

git clone <url>

When you want to configure your name we use the following commands.

git config --global user.name "Your Name"
git config --list (*when you want to list your configutration*)

How to create ssh key we use

ls ~/.ssh

When you want to make ssh key we use

ssh-keygen -t ed25519 -c (*followed with your email address*)

When you want to create ssh agent we use

eval"$(ssh-agent -s)

When you want to create a folder in git bash

mkdir (your folder name)

When you want to get into the folder you have create we use

mkdir cd

If you want touch a file in the existing folder

touch (folowed by file name)

if you want to make branches on git bash

git branch               # List branches
git branch new-branch    # Create branch
git checkout new-branch  # Switch branch
git checkout -b new-one  # Create & switch
git merge branch-name    # Merge branch

when you want to Undo / Fix Mistakes on GitBash

git restore file.txt
git reset HEAD file.txt
git reset --hard

When you want to save you work temporarily on GitBash we use

git stash
git stash list
git stash po

When you want to view your past history we use the following commands

git log
git log --oneline
git diff

Connecting git bash to git hub we use

ssh .T git@github.com