Define a view and a trigger, Database Management System

Assignment Help:

Define a view and a trigger. Construct a view for the above relations that have the information about suppliers and the elements they supply. The view holds the S#, SNAME, P# , PNAME renamed as SNO,  NAME, PNO,  PNAME.

View - A view is a virtual table that is based on the one or more physical tables and/or views. Instead, a  view  is  a  named  table  which  is represented,  not  through  its  own physically separate stored data, but through its definition in terms of other named tables (base tables or views).

Trigger - A trigger is a procedure which is automatically invoked through the DBMS in the response to specified modification to the database. Triggers might be used to supplement declarative referential integrity, to enforce multifaceted business rules or to audit changes to data.

Command:

CREATE VIEW SUP_PART (SNO, NAME, PNO, PNAME) AS

SELECT S.S#, SNAME, P.P#, PNAME

FROM S, SP, P

WHERE S.S# = SP.S# AND P.P# = SP.P#

 


Related Discussions:- Define a view and a trigger

Write short notes on transaction state, Write short notes on transaction st...

Write short notes on transaction state? A transaction may not always complete its implementation successfully such a transaction is termed aborted A transaction must be in o

Aggregation, Aggregation : One limitation of the E-R diagram is that they d...

Aggregation : One limitation of the E-R diagram is that they do not permit representation of relationships between relationships. In such a case the relationship along with its ent

Define physical and logical data independence, Define physical and logical ...

Define physical and logical data independence. How does this architecture help in achieving these? Data independence entails that change in one view must not need a change in t

How to control as concurrent tasks, Control as Concurrent Tasks The ex...

Control as Concurrent Tasks The expression control as simultaneous task means applying control for those events of object which can happen simultaneously. An object can be imp

Define sequence, Define Sequence A sequence is a set of integers 1, 2, ...

Define Sequence A sequence is a set of integers 1, 2, 3 that are generated in order on demand. Sequences are regularly used in databases because lots of applications require ev

ER model, coventions for displaying an ER schema as ER diagram

coventions for displaying an ER schema as ER diagram

What is a name, What is a Name? A user-supplied name is used for identi...

What is a Name? A user-supplied name is used for identity. This form of identity is used for files in file systems. The user gives every file a name that uniquely identifies it

Lossless-join decomposition, Lossless-Join Decomposition   Let us sh...

Lossless-Join Decomposition   Let us show an intuitive decomposition of a relation. We require a better basis for deciding decompositions since intuition may not always be r

Data, Explain three main attributes of data.

Explain three main attributes of data.

What are the situations while dbms should not be used, What are the situati...

What are the situations while DBMS should not be used? DBMS should not be used in situations like: (i) No need of security. (ii) Not difficulty to access the data (iii) N

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