JMN ACADEMY

1. Introduction to Oracle Database 21c Express Edition (XE) - Free, lightweight version of Oracle Database - Ideal for learning and small-scale applications - Limited to 12GB of user data and uses up to 2GB of RAM 2. Installation and Setup 2.1 Installing Oracle 21c XE 1. Download Oracle 21c XE from: https://www.oracle.com/database/technologies/xe-downloads.html 2. Run the installer:    - Windows: Double-click the .exe file    - Linux: Use `rpm` or `yum` command 3. Follow the installation wizard:  Accept the license agreement Choose an installation location (default is usually fine) Set a password for the SYS, SYSTEM, and PDBADMIN accounts (write this down!) Select the option to start the database service automatically (recommended)  4. Complete the installation: Wait for the installation process to finish Note down the database connection details provided at the end The default container database (CDB) name is XE The default pluggable database (PDB) nam...

 Getting Started with MySQL Introduction to MySQL Definition: MySQL is an open-source relational database management system (RDBMS) Uses: Web applications, data warehousing, e-commerce, logging applications Key features: Speed, reliability, scalability, and ease of use Installing MySQL Download MySQL Community Server from official website Follow installation wizard for your operating system Set root password during installation Verify installation: mysql --version MySQL Command-line Client Accessing MySQL: mysql -u root -p Basic commands: SHOW DATABASES ; CREATE DATABASE mydb ; USE mydb ; SHOW TABLES ; MySQL Workbench Introduction: Visual tool for database design and management Key features: SQL development Data modeling Server administration Example: Creating a new connection New Connection > Enter details (hostname, username, password) PHPMyAdmin Web-based MySQL administration tool Often comes pre-installed with web hosting packag...

 PK - Primary Key: Uniquely identifies each record in a table. NN - Not Null: Ensures a column cannot have a NULL value. UQ - Unique: Ensures all values in a column are different. B - Binary: Stores binary byte strings. UN - Unsigned: For numeric types, allows only non-negative values. ZF - Zero Fill: Pads numeric values with zeros to the left. AI - Auto Increment: Automatically generates a unique number for new records. G - Generated Column: Value is computed from an expression. PK - Primary Key A primary key uniquely identifies each record in a table. It must contain unique values and cannot have NULL values.  Example: CREATE TABLE Students ( StudentID INT PRIMARY KEY , Name VARCHAR ( 50 ) , Age INT ) ; Here, StudentID is the primary key. NN - Not Null  This constraint ensures that a column cannot have NULL values.  Example: CREATE TABLE Employees ( EmployeeID INT PRIMARY KEY , Name VARCHAR ( 50 ) NOT NULL , Email VA...

 1. Database Definition: A database is a structured collection of data stored and managed electronically. It allows for efficient data retrieval, manipulation, and management. Characteristics: - Structured : Data is organized in tables with rows and columns. - Persistent: Data remains available over time. - Accessible : Allows querying and manipulation through a Database Management System (DBMS). 2. Database Management System (DBMS) Definition: A DBMS is software that facilitates the creation, manipulation, and management of databases. It provides an interface for users and applications to interact with the data. Characteristics : - Data Definition: Allows creation and modification of database schemas. - Data Manipulation : Supports querying, updating, and deleting data. - Data Security: Manages user access and data integrity.  3. Table (Relation) Definition: A table, also known as a relation, is a collection of rows and columns used to store data in a relational database. C...

Database keys are fundamental to relational database design, ensuring data integrity, uniqueness, and efficient data retrieval. They also play a crucial role in establishing relationships between tables. Let's explore each type of key in detail using an expanded student records example. Student Table 1. Super Key Definition : A super key is a set of one or more attributes (columns) that uniquely identifies a record in a table. Characteristics: - Uniqueness : A super key can have multiple attributes and still uniquely identify each record. - Can contain extra attributes not necessary for unique identification - Any superset of a key is also a super key - May include redundant attributes Examples in Student Table: - {StudentID} - {StudentID, FirstName} - {StudentID, Email} - {StudentID, FirstName, LastName, Email} - {Email, PhoneNumber} Importance: Super keys form the basis for understanding and identifying more specific types of keys. They help in recognizing all possible combinatio...

  Flat File Systems (1950s-1960s) Earliest form of data storage Characteristics: Data stored in plain text files Each line represents a record Fields separated by delimiters (e.g., commas, tabs) Advantages: Simple and easy to understand Suitable for small amounts of data Disadvantages: Data redundancy Lack of data independence Difficult to manage relationships between data Limited data integrity and security Example use: Early payroll systems Hierarchical Model (1960s) Introduced by IBM with Information Management System (IMS) Structure: Tree-like structure with parent-child relationships One parent can have multiple children, but each child has only one parent Characteristics: Based on parent-child relationships Efficient for one-to-many relationships Advantages: Fast data retrieval for hierarchical queries Good for applications with natural hierarchies (e.g., organizational structures) Disadvantages: Inflexible structure Difficulty in rep...

 DBMS Types Hierarchical DBMS: Structure: Data organized in a tree-like structure with parent-child relationships. Example: IBM's Information Management System (IMS) Use case: Organizational charts, file systems Imagine a family tree: Grandparent Parent 1 Child 1 Child 2 Parent 2 Child 3 Network DBMS: Structure: Data organized in a graph-like structure allowing many-to-many relationships. Example: Integrated Data Store (IDS) Use case: Complex relationship modeling Think of a social network: Person A is friends with Person B and Person C Person B is friends with Person A and Person D Person C is friends with Person A and Person D Relational DBMS: Structure: Data organized in tables with rows and columns, using relationships between tables. Examples: MySQL, Oracle, PostgreSQL Use case: Most common type, used in various applications Imagine a library system: Books table: (ID, Title, Author, ISBN) Members table: (ID, Name, Address, Phone) Loans table...