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9. What are Constraints?
Ans. Constraints are rules that enforce data integrity within a database. They define the conditions that must be met for data
to be inserted, updated, or deleted in a table. Common types of constraints include primary key constraints, foreign key
constraints, unique constraints, and check constraints.
10. What is SQL?
Ans. Structured Query Language (SQL) is the standard language for managing relational databases and performing various
operations on the data in the tables. It would enable us to store, retrieve, and manipulate data in the tables.
B. Long answer type questions.
1. Identify the data type of a given column in table: Airlines.
Columns Data Type
Flight_No
NoOfPassengers
Airline_Name
Arrival_Time
Departure_Time
Fares
Ans. Columns Data Type
Flight_No Text
NoOfPassengers Integer
Airline_Name Text
Arrival_Time Date/Time
Departure_Time Date/Time
Fares Float
2. Define the following:
a. Data Model b. Database c. Tables
Ans. a. Data Model: A data model in database management systems is a conceptual representation of how data is organised
and structured within the database. It defines the relationships between different types of data, the constraints that
apply to the data, and the operations that can be performed on the data.
b. Database: A database is a collection of logically related data items stored in an organised manner. The information
being stored in a database can be added, modified, deleted or displayed according to the requirements of the user. We
are using a database in almost every field. It is used by the school to store information about students and books in the
library. When we go shopping then the shopping complex uses a database to maintain the details of stock and customers.
Companies use databases to keep track of their employees' information.
c. Tables: Tables are the basic structure of a database where data is stored. A table is a collection of logically related records.
It is organised as a set of columns, and can have any number of rows. Each row represents a record, while each column
represents a field or attribute.
3. The structure of a table “ITEM” is given below. Suggest suitable data type and size of each column. Also, identify the
primary key in this table.
NAME DATA TYPE SIZE
ITEMNO
NAME
PRICE
QUANTITY
AMOUNT
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