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
To do the division operation R1 ÷ R2, R2 should be a correct subset of R1. In the following example R1 have attributes A and B and R2 have only attribute B so R2 is a correct subse
CREATE YOUR DATABASE TABLES Your database project must have a minimum of four tables. Include the SQL scripts used to create the tables in your documentation. Explain the tables
Find out the names and company names of all employees sorted in ascending order of company name and descending order of employee names of by which company. SELECT EMPLOYEE_NAME,
What is Identity? Identity (or AutoNumber) is a column that automatically produces numeric values. A start and increment value can be set, but most DBA leave these at 1. A GUID
Developer is required to do a task including: - Database Normalization - Database Analysis - ERM Diagram Details can be provided and then you can change your bid accord
Question: In a multi-user database environment, locking mechanisms can be used to solve the three basic problems of concurrency. On the other hand, however, locking may also le
what are the limitations of dbms?
Describe logical data independence ? Logical Data Independence - It is the capacity to modify the conceptual schema without having to change external schemas or application p
Synonyms and Indexes Some of the essential properties of indexes are: An Index is a schema Object Indexes can be formed explicitly or automatically Indexes are m
Command Line Interfaces: These are interactive interfaces, character-based that let you use the complete power and functionality of the DBMS query language directly. They permit yo
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