Define query by example, Database Management System

Assignment Help:

Define Query by Example

QBE is a query language relies upon domain calculus and has two dimensional syntax. The queries are written in the horizontal and vertical dimensions of table. Queries are made by entering an instance of a possible answer in a skeleton table as displayed in the following diagram: 

1387_Query-By-Example.png

Conditions particular in a single row are ANDed and conditions illustrated in separate rows are ORed. The tuple operations are P., I ., etc., for PRINT, insert commands, resp. The variable names are illustrated by preceding their name with an underscore. QBE as well provides a "conditions" box to specify additional constraints that is why the conditions that cannot be added in a Skelton table can be entered in the conditions table. The aggregation operations such as max., min, sum. etc. are also provided by QBE.


Related Discussions:- Define query by example

Determine bcnf-dcnf and key relation, (A) For the relation; CarSales (R...

(A) For the relation; CarSales (RegNo, BuyerName, Address, SalesPerson, Make, Model, Commission) The following functional dependences hold, RegNo _ID à Make, Model Reg

#, How to use Oracle

How to use Oracle

Process of adjustment of inheritance, Process of Adjustment of inheritance ...

Process of Adjustment of inheritance During object design, inheritance is readjusted by rearranging classes and operations, and abstracting common behaviour.

Define blocks, Define blocks? The database system resides eternally on ...

Define blocks? The database system resides eternally on non-volatile storage, and is into fixed-length storage units known as blocks.

Explain the components of database system in details., Explain the compone...

Explain the components of Database System in details.

Describe identifying relationship, Describe identifying relationship? ...

Describe identifying relationship? Identifying relationship: It is relationship among strong entity and a weak entity it is represented through a doubly outlined diamond in C

Explain the need of parallel database, Probelm: a) In the context of OO...

Probelm: a) In the context of OODBMS, define the following terms with appropriate examples. (i) Object class. (ii) Abstract class. (iii) Aggregation. (iv)

Access, I have to solve a problem using access

I have to solve a problem using access

What is enterprise resource planning, What is Enterprise Resource Planning ...

What is Enterprise Resource Planning (ERP), and what kind of a database is used in an ERP application? Enterprise Resource Planning (ERP) is an information system used in manuf

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