What is a view in sql and when can views be updated, Database Management System

Assignment Help:

What is a view in SQL? When can views be updated?

A view is a virtual table which consists of columns from one or more tables. Through it is same to a table; it is stored in the database. It is a query stored as an object. Therefore, a view is an object in that derives its data from one or more tables. These tables are referred to as base or underlying tables.

Views can be updated if they are described on a single table without any aggregate functions could be mapped to an update on the underlying base table under certain conditions.


Related Discussions:- What is a view in sql and when can views be updated

In tuple relational calculus p1- p2 is equivalent to, In tuple relational ...

In tuple relational calculus P1 → P2 is equivalent to ? A In tuple relational calculus P1→  P2 is equivalent to ¬P1 V P2. (The logical implication expression A  B, meaning

Define functional and multivalued dependencies, Define functional and multi...

Define functional and multivalued dependencies.       Ans:  A functional dependency is a assets of the semantics of the attributes in a relation. The semantics point out how at

Single-valued dependencies, Single-Valued Dependencies A database is a ...

Single-Valued Dependencies A database is a collection of related information and it is therefore inevitable that some items of information in the database would depend on some

What are the dbms languages, What are the DBMS languages? Explain.  Ans...

What are the DBMS languages? Explain.  Ans: a) Data Definition Languages (DDL): It is employed to specify database schema for example CREATE DROP statements etc.     b)  Dat

Which model is record based logical model, Which model is record based logi...

Which model is record based logical model? Network Modelis basically known as record based logical model.

Define the five basic operators of relational algebra, Define the five basi...

Define the five basic operators of relational algebra? Five basic operators of relational algebra are: 1. Union (∪∪∪∪) - Selects tuples which are in either P or Q or in both

Improve efficiency in query evaluation, Question: AirwaysCentre, an int...

Question: AirwaysCentre, an international airline booking company currently uses a relational database system for their operations, which includes the following relations: P

Create a company database, Company Database: a-)Here is the ER Model ...

Company Database: a-)Here is the ER Model b-)Here is the Relational Model:     IMPORTANT NOTICE FOR SOLUTION TYPE: ***THIS ASSIGNMENT WILL BE SOLVED BY THE

State the functional approach of object oriented methods, State the functio...

State the functional approach of object oriented methods Moving from a functional approach to an object oriented one needs a translation of functional model elements into objec

Data manipulation language, Question 1 Discuss about second normal form an...

Question 1 Discuss about second normal form and third normal form Question 2 Write short note on                        1) Data Manipulation Language 2) Data Definition La

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