Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
It defines that the tuple in one relation that refers to another relation must refer to an existing tuple in that relation. This constraint is states on two relations (not essentially distinct). It uses a concept of foreign key and has been dealt with in more factors in the next unit.
Example
In the example given above, the value of C^ in every R tuple is matching with the value of C# in some S tuple. If a tuple has values (A6, B2, and C4) is added then it is invalid as referenced relation S doesn't contain C4. Therefore, it will be a violation of referential integrity constraint.
Storage Of Database On Hard Disks At this point, it is worthwhile to note the difference among the terms file Organisation and the access method. A file organisation shows to t
how can apply joins on table
(A) For the relation; CarSales (RegNo, BuyerName, Address, SalesPerson, Make, Model, Commission) The following functional dependences hold, RegNo _ID à Make, Model Reg
WRITE SHORT NOTES ON INDEX STRUCTURE OF FILES? There are two basic parts of indices 1. Ordered indices 2. Hash indices Every technique must be evaluated on the bas
explain cascading rollback
In an organization several projects are undertaken. Each project can employ one or more employees. Each employee can work on one or more projects. Each project is undertaken on the
4. Describe three ways to handle missing field values
Three way to handle missing field val
The External or View Level The external or view level is the highest level of abstraction of database. It gives a window on the conceptual view, which permits the user to see
Define instance and schema? Instance: Collection of data kept in the data base at a particular moment is known as an Instance of the database. Schema: The o
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!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd