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:
Design a gennalization and specialization hierarchy for an automobile sales company
Express the ways provided by MySQL for Pattern Matching? MySQL provides two kinds of pattern matching. 1) One is based on SQL patterns 2) Regular expressions.
Explain Transaction manager and their work? Transaction Manager: Ensure the database remains in a constant (correct) state despite system failure, and in which concurrent trans
Explain in detail the consistency model of the distributed file system you studied (GFS or AFS). Present the consistency model chosen and how it was achieved through design. Clarit
Define union compatibility? Explain why INTERSECTION of two relations cannot be performed if they are not union compatible? Two relations R(A1, A2,-------, An) and S(B1, B2,--
Consider a bank that has a collection of sites, each running a database system. Suppose the only way the databases interact is by electronic transfer of money between one another,
Every simple attribute of an entity type have a possible set of values that can be attached to it. This is known as the domain of an attribute. An attribute cannot have a value out
Write an sql statement to find what is the percentage of home policies which are from the state of Arizona out of all Home policies by Policy Value.
distributed quey processing
Write a program within embedded SQL to associative the total trip expenses of the salesman named ‘John' for the relations. EXEC SQL BEGIN DECLARE SECTION; long total_expenses;
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