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

Define timestamp ordering, Define Timestamp ordering Ans In timestamp-b...

Define Timestamp ordering Ans In timestamp-based method, a serial order is made among the concurrent transaction by assigning to every transaction a unique nondecreasing number

Special comparison operator used in where clause-dml, Special comparison op...

Special comparison operator used in where Clause a.   between. ...and...It gives range among two values (inclusive) Example: SELECT ENAME, SAL FROM EMP WHERE SAL BETWE

Describe the two alternatives for specifying structural, Describe the two a...

Describe the two alternatives for specifying structural constraints on relationship kinds? Relationship kinds have certain constraints in which limit the possible combination o

E-r model uses this symbol to represent weak entity set, E-R model uses thi...

E-R model uses this symbol to represent weak entity set ? A Doubly outlined rectangle symbol is used to represent weak entity set.

Describe about use case and external case in dfd, Describe about Use Case a...

Describe about Use Case and external case in DFD The processes are transformed those into the Use Case and external case in DFD has same characteristics which of an actor in O

Define data model, Define data model? A data model is a collection of c...

Define data model? A data model is a collection of conceptual tools for explaining data, data relationships, data semantics and consistency constraints.

Explain in detail about collaboration diagrams, Explain in detail about Col...

Explain in detail about Collaboration Diagrams Collaboration diagrams are interaction diagrams which emphasize structural organisation of an object that transmit and receive m

Checkpoint, what is check point in database management system

what is check point in database management system

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