Basics of database

by
Basic Terms
  • Data
    Data means raw facts.
    Example: Sonu, 25, Delhi
  • Information
    Information is processed data that has meaning.
    Example: Sonu is 25 years old and lives in Delhi.
Table Basics
  • A table is a collection of rows and columns.
  • Tables are used to store data in an organized way.
Database Terminology

In database language:

  • Table is called a Relation
  • Row is called a Tuple
  • Column is called an Attribute
Database

A database is a collection of one or more tables.

A database can contain:

  • Tables
  • Views
  • Triggers
  • Other database objects

RDBMS (Relational Database Management System) is a type of software used to create and manage databases.

Key points about RDBMS:

  • It stores data in the form of tables
  • Tables can be related to each other
  • It helps to store, retrieve, update, and delete data easily

ORDBMS (Object Relational Database Management System) is an RDBMS that supports object-oriented features.

Some popular RDBMS / ORDBMS software

Some of these are RDBMS, and some support object-oriented features (ORDBMS).

  • Oracle
  • Microsoft SQL Server
  • MySQL
  • MariaDB
  • PostgreSQL
  • …

... means the list is very long and cannot be shown completely.

SQL

All the RDBMS / ORDBMS listed above use SQL.

SQL stands for Structured Query Language.

SQL is used to:

  • Create databases
  • Manage databases
  • Retrieve data from databases

SQL is a standard language, which means it works with most database systems.

SQL is a fourth-generation language (4GL).