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!
Define entity integrity and referential integrity. How does SQL allow specification of these?
Ans: Entity Integrity Rule- If the attribute A of relation R is a prime attribute of R after that A cannot accept null values.
Referential Integrity Rule- In referential integrity, it is made sure that a value that appears in one relation for a given set of attributes as well appears for a particular set of attributes in another relation.
In SQL, referential integrity and entity integrity rules are implemented as constraints on the relation known as reference Key constraint and primary Key constraint correspondingly.
These constraints can be fixed with relation at the time of creation of the relations or after the creation of the relations by altering the definition of the relations. For instance:
Describe Parameteric end users? Parametric end users might be given update access, but are commonly not permitted to change the structure of data.
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
Question: a) There are three concurrency problems, i.e. three types of potential mistake which could occur if concurrency control is not properly enforced in the database syst
What are the two statements regarding transaction? The two statements regarding transaction of the form are:- A) Begin transaction B) End transaction
Define Deadlock detection If a system does not employ a few protocols that make sure deadlock freedom, after that a detection and recovery scheme should be used. An algorithm
how to find entities
Define instance and schema? Instance: Collection of data stored in the data base at a certain moment is Schema: The overall design of the data base is known as the data base
About Attribute inheritance
Why do so various organizations use MySQL? Advantages: Open source Highly efficient Offers a high scalability in terms of size and connectivity. Highly prote
How to create a table from existing table? Create table as e.g, To create a new table ‘N_emp' with employee names and their identification numbers only from employee ta
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