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Unit II: Database Query using SQL
4 DATABASE QUERY USING SQL
Chapter Outline
4.1 Database Management System (DBMS) 4.2 Relational Data Model
4.3 Structured Query Language (SQL) 4.4 SQL Statements and Functions
Introduction
In Class XI, we learned the basics of database management systems and the use of structured query language for
interacting with databases. This chapter will review the basic terminologies of Database Management Systems
(domain, tuple, relation, candidate key, primary key, and alternate key). We will also review the components of SQL:
Data Definition Language (DDL) and Data Manipulation Language (DML).
Furthermore, this chapter will explore various mathematical, text, date, and aggregate functions, equipping us with
powerful techniques for querying and manipulating data.
4.1 Database Management System (DBMS)
To retrieve valuable information from data, we need to organise the data in a form that makes it easy to retrieve and
process. Often, it is convenient to manage the data in a tabular format. Table 4.1 shows sample data about individual
student preferences of the games they want to play.
RollNo Name Game
1 Pushkar Cricket
2 Aadhira Badminton
3 Jayaprakash Cricket
4 Priyabrata Table-tennis
5 Farook Cricket
6 Amisha Cricket
7 Aayam basketball
Table 4.1
124 Touchpad Informatics Practices-XII

