Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Before we talk about the relational model in more detail, let us first define some very basic terms used in this model.
Tuple
Every row in a table shows a record and is called a tuple. A table containing 'n' attributes in a record is called n-tuple.
Attribute
The name of every column in a table is used to interpret its meaning and is known as an attribute. Every table is called a relation.
For instance, Figure shows a relation PERSON. The columns NAME, PERSON_ID, AGE and ADDRESS are the attributes of PERSON and every row in the table represents a separate tuple (record).
Relation Name: PERSON
PERSON_ID
NAME
AGE
ADDRESS
TELEPHONE
1
Sanjay Prasad
35
b-4,Modi Nagar
011-25347527
2
Sharad Gupta
30
Pocket 2, Mayur Vihar.
023-12245678
3
Vibhu Datt
36
c-2, New Delhi
033-1601138
Figure: An extended PERSON relation
When every condition appears with equality condition (=) only. c) Natural join (denoted by R*S) When two join attributes have the similar name in both relations. (Tha
Find out the names of all employees who work for first Bank Corporation from database. SELECT EMPLOYEE_NAME FROM WORKS WHERE COMPANYNAME = ‘First Bank Corporation';
1. Develop a flowchart using the decision structure to solve the following problem. A Box Lunch Bonanza is a small catering company that offers 2 different types of box lunches
How to reduce data redundency
ERD Diagram of Medical Recruitment Agency?
Discuss the methods for a hash file to expand and shrink dynamically. What are the advantages and disadvantages of each? The hashing methods that permit dyanamic file expansi
Explain the following functions of Oracle with suitable examples: (i) To_Char( ) (ii) Count( ) (iii) Trim( ) (iv) Length( ) Ans: (i) To_char( ): The TO_CHAR function conver
Design Of Distributed Databases: The distributed databases are mainly relational at local level. So a local database schema is the similar as that of a centralised database design
What is a candidate key? Minimal super keys are known as candidate keys.
What are partial, alternate,, artificial, compound and natural key? Partial Key: It is a set of attributes that can uniquely recognize weak entities and that are related to s
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd