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:
What is schema
Physical Database Design Issues The database design includes the process of logical design with the use of E-R diagram, normalisation, etc., followed by the physical design.
aggregation
Which database level is closest to the users? External database level is closest to the users.
What are aggregate functions? And list the aggregate functions supported by SQL? Aggregate functions are functions that take a collection of values as input and return a one va
What is system log? What are the entries? Ans: The system log that is generally written on stable storage contains the redundant data required to recover from volatile
You must implement the entity relationship model provided in the model solution to Assignment 1. The model solution will be released on the course website approximately TWO (2) we
Inheritance Adjustment As in object oriented analysis and design terms inheritance defines a relationship between classes, where as one class shares structure or behaviour def
Explain the terms primary key, candidate key, alternate key and secondary key. In the given table identify every key? STUDENT(SID,Regno, Name, City) Primary Key: The prim
To do the division operation R1 ÷ R2, R2 should be a correct subset of R1. In the following example R1 have attributes A and B and R2 have only attribute B so R2 is a correct subse
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