DATABASE Purpose of database Database – Database is a collection of related information that is organized in such a way that supports for easy access, modify and maintain data. Purpose of database It redues data redundancy Database can control data inconsistency It facilitate data sharing Database enforce standards Database can ensure data security Integrity can be maintained through databases

DBMS (Database Management System) - The database is managed by some special software packages known as Database Management Systems (DBMS). The purpose of DBMS software is to allow the user to create, modify and administration of database.

RDBMS – Relational Database Management System Relation - Marks Primary Key Relation - Student Foreign Key ID NAME ADDRESS 1 Meenu Dubai 2 radha Sharjah 3 Lal Attribute ID SUBJECT MARK 1 MATHS 60 2 70 3 90 ENGLISH 87 Tuple

Definitions Relation(table) - Data arranged in rows and columns Tuple (record) – Row of a relation Attribute (field) – Column of a relation Cardinality of a relation – Number of tuples in a relation Degree of a relation – Number of columns in a relation Primary key – Set of one or more attribute that can uniquely identify the tuples within a relation. Foreign key – Non key attribute which is the primary key of another table Candidate key – Attribute that can serve as primary key Alternate key – Candidate key which is not a primary key

SQL (Structured Query Language) is a standard language for accessing and manipulating databases

SQL (Structured Query Language) DDL (Data Definition Language) DML (Data ManipulationLanguage)

SQL (Structured Query Language) DDL DML Data Definition Language (DDL) or Data Description Language (DDL) statements are used to define different structures in a database. DDL statements are used to create structure of a table, modify the existing structure of the table and remove the existing table Data Manipulation Language (DML) statements are used to insert data into tables, delete data from the tables, retrieve data and modify the existing data. Create table ->to create table Alter table->to modify table Drop table ->to delete table Insert->to insert values in a table Update ->to modify data Delete ->to delete data Select ->to get the data from table