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Ans. NAME DATA TYPE SIZE
ITEMNO NUMERIC 5
NAME VARCHAR 35
PRICE DECIMAL 5
QUANTITY NUMERIC 5
AMOUNT DECIMAL 5
4. Consider the following table:
EmpNo EmpName Designation
111 Sahil Executive
222 Anup Manager
333 Mansi Head
444 Pooja Executive
Using the above table, answer the following questions:
a. Identify the Primary key.
b. EmpName has all the unique names. Can it work as a primary key? Justify your answer
Ans. Primary Key – EmpNo
No, EmpName cannot work as a Primary key because it may have unique values, but there are chances that a new employee
with the same name can join the company, so the field will have duplicate values and cannot be used as a primary key.
5. Find out which of the following fields of table "Bank" can be selected as primary key, candidate key and alternate key?
Acc_No, Cust_Name, DOB, PAN_No, Opening_Bal.
Ans. Primary key - Acc_No
Candidate key - Acc_No and PAN_No
Alternate key - PAN_No
6. Differentiate between a Primary key and Foreign key. Explain with the help of an example.
Ans. Feature Primary Key Foreign Key
Definition A primary key uniquely identifies A primary key of one table when used
each record (row) in a table. in another table is called foreign key.
Uniqueness Must contain unique values. Values do not have to be unique.
Null Values Does not allow NULL values. Allows NULL values unless specified
with NOT NULL.
Purpose Ensures entity integrity for the Maintains referential integrity
table. between two related tables.
Usage Used to uniquely identify rows in Used to create a relationship between
a table. tables.
Constraint Automatically creates a Unique and Enforces data integrity by linking
Non-Null constraint. tables via referenced keys.
Example StudentID in Students table. StudentID in Grades table referencing
Students(StudentID).
7. List Numeric and Alphanumeric Datatypes in LibreOffice Base.
Ans. The numeric data types are used to store data in the form of numbers which can be integers or real numbers with decimals.
Arithmetic operations can be performed on numeric data.
Data Type Name Signed Description
Tiny Integer TINYINT No Store integer range between 0 to 255
15
15
Small Integer SMALLINT Yes Store integer range between -2 to + 2 -1
Database Management System using LibreOffice Base 375

