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

Describe the algorithm to draw the dependency graph, Describe the algorithm...

Describe the algorithm to draw the dependency graph?   Ans: Algorithm to draw Precedence Graph is like this: a.  For every transaction T i participating in schedule S, make

What are advantages of object-oriented programming paradigm, What is the ma...

What is the major advantage of object-oriented programming paradigm? The ability to modify the explanation of an object without affecting the rest of the system is the main adv

Explain how the associations are implemented as classes, Explain how the as...

Explain how the associations are implemented as classes. A general approach in this case is to transform an association class into a simple class linked to two original classes

Construct a conceptual data model, Competition entrants can be either Indiv...

Competition entrants can be either Individuals, or Teams. A Team is usually sponsored by a business, and, in that case, the team members would all wear T-shirts with the sponsoring

What is the use of unique function, What is the use of unique function? ...

What is the use of unique function? UNIQUE function: If UNIQUE is specified then only unique values are used to computed the mean.

Order by clause-data manipulation language, Order by clause By usin...

Order by clause By using this rows can be sorted It is used in the last portion of select statement By default it gets ascending order DESC: is used

HRM, is Chipo carrying his baby

is Chipo carrying his baby

Define normalization, Normalization :It is a process of examine the given ...

Normalization :It is a process of examine the given relation schemas based on their primary key and Functional Dependencies (FDs) to achieve the properties Minimizing redun

Where and having clause in sql, WHERE and HAVING clause in SQL ? The WH...

WHERE and HAVING clause in SQL ? The WHERE clause is commonly used for implementing conditions on each tuple of the relation. The HAVING clause is used in combination along wi

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