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
i want to database for online assignment submission system
how many hourse have been spent on a certain project
Boyce-Code Normal Form (BCNF) A relationship is said to be in BCNF if it is already in 3NF and the left hand side of each dependency is a candidate key. A relation who is in 3N
An example of a weak entity is Staff because the availabilityID cannot be uniquely identified unless it is used in conjunction with the foreign key known as availabilityID in the A
Logical Operators Rules of Precedence: Order evaluated Operator 1 All comparison operators 2
What is known as heap file organization? In the heap file organization, any record can be placed anywhere in the file where there is space for the record. There is no ordering
What are the different approaches for database design? There are two basic approaches for database design which are as follows: Attribute driven: It compiles a list of att
The issues relating to the Design of the Physical Database Files Physical File is a file as stored on the disk. The major issues relating to physical files are: • Cons
A student entity type has the following attributes,name..
What is disadvantage of multiple inheritances? There is potential ambiguity if the similar variable or method can be inherited from more than one superclass.eg: student class m
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