Session 1: Introduction to Data

1. What is Data?

• Definition: Data is a collection of recorded information that can be analysed for decision-making.
• Examples of Data:
  • Fitness trackers: Steps, heart rate, calories burned.
  • Measurements: Floor dimensions, furniture sizes.
  • Text Data: Word count in a book, occurrences of a word.

2. What is a Database?

• Definition: A structured collection of related data, stored electronically.
• Examples:
  • Online to-do lists
  • Contact lists (Phone numbers, names, emails)
  • Shopping lists (Items, prices, quantities)

3. Why Do Businesses Collect Data?

• Market Analysis: Track trends, compare competitors.
• Product Performance: Monitor product usage, downtime, customer feedback.
• Decision Making: Use facts instead of guesses.
• Customer Understanding: Gather insights via surveys, interactions.
• Risk Management: Identify problems before they happen.
• Business Goals: Data-driven decisions for growth.

Session 2: Introduction to Databases

1. Structured vs Unstructured Data

• Structured Data: Organized, searchable, stored in tables (e.g., Excel sheets).
• Unstructured Data: Unorganized, complex processing required (e.g., emails, social media posts, handwritten notes in hospitals).

2. What is a Relational Database?

• Definition: A database that organizes data into structured tables with relationships between them.
• Tables consist of:
  • Rows (Records): Each represents an entity (e.g., an employee).
  • Columns (Attributes): Each represents a data type (e.g., name, salary).

3. Relational Database Management System (RDBMS)

• Definition: Software that enables interaction with relational databases.
• Popular RDBMS:
  • MySQL (Used in this course)
  • Oracle
  • PostgreSQL

Session 3: MySQL & DBeaver

1. What is SQL?

• SQL (Structured Query Language): A programming language for communicating with databases.
• Uses of SQL:
  • Create, update, delete, and manage databases.
  • Perform data queries and manipulations.

2. What is a Server?

• Definition: A computer that provides services (e.g., stores databases).
• SQL Server: A server specifically for managing SQL-based databases.
• Example: MySQL Server (Open-source, relational, cross-platform).

3. Setting up MySQL

• Installation Steps:
  1. Download MySQL Community Server.
  2. Choose the correct OS version (Mac/Windows).
  3. Follow installation prompts.
  4. Set up a root password (IMPORTANT: Save this).

4. Setting up DBeaver

• DBeaver: A database management tool used to interact with databases visually.
• Installation Steps:
  1. Download DBeaver Community (free version).
  2. Install and open the application.
  3. Connect it to MySQL Server using the saved root password.

Session 4: SQL Basics & Data Types

1. Who Uses SQL?

• Data Analysts (Analyse trends, insights).
• Business Intelligence Professionals (Create reports, dashboards).
• Financial Analysts (Forecasting, budgeting).
• Software Developers (Database management).

2. What is an SQL Query?

• Definition: A command used to retrieve data from a database.

Example:
sql
CopyEdit
SELECT * FROM employees WHERE age = 21;

• • Retrieves employees aged 21.

3. Data Types in SQL

• Integer (INT): Whole numbers (e.g., 25, 50, 100).
• Decimal (DECIMAL(M,D)): Numbers with decimals (e.g., 99.99).
• Varchar (VARCHAR(N)): Text (e.g., names, descriptions, max 255 characters).
• Boolean (BOOLEAN): True (1) or False (0).
• Date (DATE): Stored as YYYY-MM-DD.

Demo: Creating a Table in MySQL

Steps to Create a Table

Syntax Example:
sql
CopyEdit
CREATE TABLE equipment_maintenance (

    equipment_id INT,

    maintenance_cost DECIMAL(10,2),

    description VARCHAR(255),

    task_is_operational BOOLEAN,

    last_maintenance_date DATE

);

•  
• Key Takeaways:
  • Equipment ID: Uses INT (Whole numbers).
  • Maintenance Cost: Uses DECIMAL(10,2) (Max 10 digits, 2 after decimal).
  • Description: Uses VARCHAR(255) (Max 255 characters).
  • Task Status: Uses BOOLEAN (0 for False, 1 for True).
  • Last Maintenance Date: Uses DATE (YYYY-MM-DD format).

Final Notes

• SQL is an essential tool for managing and analysing data.
• Databases help structure large amounts of information efficiently.
• DBeaver provides an easy interface for managing MySQL databases.
• Data types are crucial to storing and retrieving accurate information.

https://www.youtube.com/watch?v=JLSk10rC3p4&ab_channel=CodeFirstGirls