Computer Science · Class 8
Database Introduction
Learn Database Introduction with notes, examples, and practice questions.
3 sections15–25 min read6 MCQs · 2 examples
Chapter Overview
Database Introduction introduces storing and retrieving data using databases, tables, keys, and SQL queries for Class 8.
Database Concepts
- Database: organised collection of data
- Table: rows (records) and columns (fields)
- Primary key uniquely identifies record
- DBMS manages databases
SQL Basics
- SELECT reads data; INSERT adds rows
- UPDATE changes; DELETE removes
- WHERE filters rows
- ORDER BY sorts results
Solved Examples
Step-by-step solutions — read each step before checking the final answer.
SELECT query
Write SQL to list all student names.
- 1SELECT name FROM students;
- 2FROM specifies table
Answer
SELECT name FROM students;
Primary key
Why does each student record need a unique ID?
- 1Avoid duplicate records
- 2Primary key identifies row uniquely
- 3Enables reliable updates
Answer
Unique identification
Key Points to Remember
- ✓ RDBMS: MySQL, PostgreSQL, SQLite
- ✓ Never put passwords in plain SQL strings
- ✓ Normalisation reduces redundancy
Exam Tips
- • Write SELECT with WHERE
- • Know DDL vs DML
- • Define primary and foreign key
Practice MCQs — Database Introduction
Test your understanding with topic-wise multiple choice questions. Explanations appear after each answer.
Question 1 of 6Score: 0/0
SQL SELECT is: