Example of relational operations, Database Management System

Assignment Help:

Consider the relation PERSON. If you want to display details of persons having age less than or equal to 30 than the select operation will be used as follows:

σ AGE <=30 (PERSON)

The resultant relation will be as shown:

PERSON_ID

NAME

AGE

ADDRESS

2

Sharad Gupta

30

Pocket 2, Mayur

Vihar.

 

 

 

Note:

1)   Select operation is commutative; i.e.,

σ (R)) = σ (R))

Therefore, series of select can be applied in any order

2) More than one condition can be applied using Boolean operators OR & AND etc.


Related Discussions:- Example of relational operations

Define page, Define page. The database is partitioned into some number ...

Define page. The database is partitioned into some number of fixed-length blocks, which are referred to as pages.

desirable properties of decomposition, Desirable Properties Of Decompositi...

Desirable Properties Of Decomposition Decomposition is a process of dividing a relation into its projections that will not be disjoint. Please remind the Relational projection

Original Database, I need an ERD created for any original database(can be o...

I need an ERD created for any original database(can be on anything). It needs to be 3NF. I then need all the CREATE STATEMENTS, INSERT STATEMENTS(anything you can think of as long

RDM & ER Modelling, #questiRegional Gardens has many nurseries, including W...

#questiRegional Gardens has many nurseries, including Wagga Wagga, Bathurst, Albury, Orange, and Dubbo. Each nursery is known by its campus code, eg WW, B, A, O and D respectively.

Data control, Data Control The data control mostly refers to commands that...

Data Control The data control mostly refers to commands that permit system and data privileges to be passed to several users. These commands are usually available to database admi

Describe the objective of structural diagrams, Describe the objective of St...

Describe the objective of Structural Diagrams The main objective of structural diagram is to visualize, construct, specify and document static aspects of a system. Their eleme

Support by adding indexes, Support by Adding Indexes Multiple indexes c...

Support by Adding Indexes Multiple indexes can be used to access a data file by multiple access paths. In such a scheme only single copy of the data is consider, only the numbe

Farm management system, draw er diagram using entities crop,employee,depart...

draw er diagram using entities crop,employee,department,plot,cultivation plan,machinery,seed,fertilizer

Business process model, Consider a research paper submission process. The p...

Consider a research paper submission process. The process starts when an author submits a draft research paper (the paper may have up to 3 authors) to the chair of the organizing c

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

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!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd