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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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