DATA MODELLING RELATIONSHIPS AND SCHEMAS IN POWER BI

ndinda515 — Tue, 30 Jun 2026 18:42:48 +0000

INTRODUCTION

When I started using Power BI, I only thought of visuals like charts and graphs. However, as I progressed, I discovered a great data dashboard is built on great data models.

Data Modelling is the process of organizing your data tables and defining how they relate to each other so Power BI can combine them into meaningful reports and dashboards. Good, designed data makes it easier and faster to maintain.

Why is data Modelling Important

Well-organized data makes it easier to manage data.

Reduction of the duplicates.

Ensures data consistency.

Understanding Relationships

Relationships allow the data table to give communication using fields.

For example,
Customer Table stores all information about a customer.
Product Table store product details
Sales Table stores all information about the transactions.

Power BI connects the information between the customer’s name and Customer Id rather than repeating them it connects the information using joins.

Going through relationships I discovered schemes. Scheme is the way tables are organized in databases. There are different types of schemes e.g. Star Schema, snowflake schema and Flat table.

Star Schema

A star schema is a data model with one central fact table and dimension table surrounding it.

Fact table

A table that stores events, transactions of what happened.
• Total sales
• average sales
• quantity sold

Dimension table

A dimension table describes the items in the fact table. The table contains descriptive information.
• The customer table describes the customer
• How much sales were made

The fact table sits in the center, while the dimension tables surround it—forming a star.

Dashboard designs

A good dashboard has to fit one page.

A dashboard should show critical information.

Update automatically when data changes.

Focus on data understanding and decision making.

Conclusion

Power BI taught me that a great report are built from a a great dashboard which is achieved by having great models.

Structuring a data into facts and dimension table and choosing star schema creates a powerful model.

Data cleaning is important because a clean data is the best.

Power BI has changed how I interpret and interact with data.

How Excel is Used in Real-World Data Analysis

ndinda515 — Sun, 07 Jun 2026 11:56:14 +0000

Introduction

Microsoft Excel is a powerful software spreadsheet tool developed by Microsoft to be used for data collection, analyzation, organization, visualization and calculation for decision making purposes.
Excel is a tool that collects, organizes, allowing for data storage and analysis.

Key Components of Excel Interface

Ribbon- Contains tabs and commands (Home, Insert, ......)
Range- The group of cells selected (B:1:B44 represents range of cells in column B)
Row- Also known as a record and runs horizontally. They are labelled in numbers (e.g. 1,2)
Column- Also known as Field and runs vertically. They are labelled with letter (e.g. A, B)
Cell- Intersection of a column and a row. (e.g. A2)

Uses of excel in real-world

Data Analysis- It is used in cleaning, sorting and filtering data that is used by for both personal and business. This data is used in identification of trends and tracking data.
Accounting and Finance- It is used in preparing budgets and cashflow, recording transaction, calculating taxes and payroll etc.
Sales and marketing- To monitor sales performance, store the customer database and analyze the trends.
Project management: Monitor the project cost, track the projects, prepare reports and ensure the projects are concluded on time.
Excel can be used on the personal level to track expenses, monitor savings, budgeting and planning for financial goals.
Organizations can use the excel to track the employee's attendance sheet, maintain records and manage the leave schedules.

Key Excel Features

Data Sorting: Arranging data in specific order.
They are arranged in different types i.e. Text sorting (A to Z), Number sorting (smallest to largest or largest to smallest) and Date Sorting (Oldest to Newest or Newest to Oldest)
Filtering: Allowing the display of the only important row that meet the certain criteria that you need to use.
Data Validation: Allowing accurate and consistent data entry.
Freezing Panes: Keep headers or important columns in view as you scroll.

Excel Functions
Excel is made of different functions that summarize, analyze and automate data.
The functions perform specific task in the excel spreadsheet.
SUM () - Adds numbers in the range of a cell e.g. =sum (A1:A34) Adds numbers from A1 to A34.
MIN () - Finds the smallest number e.g. =min (D1:D7)
MAX () - Finds the largest number e.g. =max (F4:F13)
AVERAGE () - Calculates the mean value of the database selected e.g. =Average (C1:C5) Gives the mean from C1 to C5
COUNT IF () - Counts the number of cells that meet a specific criterion and can only use one condition e.g.=Count if (A1:A10,"SALARY")
COUNT IFS () -Counts the number of cells that meet a specific criterion and can use multiple conditions e.g.=Count ifs (A1:A10,"SALARY", C1:C10,">500")

Learning Excel changed how I see data by helping me view the data as information rather than just the numbers in the excel. Excel taught me how to sort, analyze, visualize and collect data making the work easier by uncovering the insights of large amount of information. As a result of Excel, I can make more informed decisions based on the information given and solve the problems efficiently and clearly. I can also give the correct prediction of the future information.

DEV Community: ndinda515

DATA MODELLING RELATIONSHIPS AND SCHEMAS IN POWER BI

How Excel is Used in Real-World Data Analysis