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

Objectives-transactions and concurrency management, Objectives After Re...

Objectives After Reading this part, you should be able to: Explain the term CONCURRENCY; Describe the term transaction and concurrent transactions; Talk about co

Relational database integrity, A database is a set of data. But, is the dat...

A database is a set of data. But, is the data kept in a database trustworthy? To answer that query we must first answer the question. What is integrity? Integrity simply means t

ER Diagram, Soccer player ER Diagram to Relational database schema

Soccer player ER Diagram to Relational database schema

Explain the structure of well formed formulae, Explain the structure of wel...

Explain the structure of well formed formulae in relational calculus. Ans: a. An atom is a formula b. If P1 is a formula, after that so are ¬P1 and (P1) c. If P1 and P2 a

Explain hash file organization, Explain hash file organization? Hash fu...

Explain hash file organization? Hash functions a) The distribution is uniform Hash functions assign each bucket the similar number of search -key values from the set of a

List the armstrong axioms for functional dependencies, List the Armstrong's...

List the Armstrong's axioms for functional dependencies.  What do you understand by soundness and completeness of these axioms?      Ans: The Armstrong's axioms are: F1:

Write a qbe query to display names of cs department, Consider a table stude...

Consider a table student (std_id, std_name, date_of_birth, percent_marks, dept_name). Write a QBE query to display names of Computer Science department students who have scored mo

What is a sub-query, (a) What is a Sub-Query? (b) What is the differen...

(a) What is a Sub-Query? (b) What is the difference between a scalar sub-query and a tabular sub-query? (c) Write an equivalent SQL statement to get the Name of Product wh

Explain trivial dependency, Explain trivial dependency? Functional depe...

Explain trivial dependency? Functional dependency of the form α ->β. is trivial if α C β. Trivial functional dependencies are satisfied by all the relations.

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