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 no primary key value can be null. This is as the primary key is used to recognize individual tuple in the relation. So we will not be able to recognize the records uniquely containing null values for the primary key attributes. This constraint is specified on single individual relation.
Example: Let R be the Table
A#
B
C
Null
B1
C1
A2
B2
C2
B3
C3
A4
B4
A5
C5
Note:
1) '#' shows the Primary key of a relation.
In the relation R above, the primary key has null values in the tuples t1 & t3. NULL value in primary key is not allowed, therefore, relation instance is an invalid instance.
statical data
List the table modification commands in SQL? A) Deletion B) Updates C) Insertion D) Update of a view
In the architecture of a database system which external level used? In the architecture of a database system view external level used.
What is Message switching Message switching transmits data units which can be arbitrarily long. Packet switching has a utmost packet size, if any message longer than that, it s
Define the Canonical cover Ans: A canonical cover F c for F is a set of dependencies like F logically implies all dependencies in F c , and F c logically entails all dependen
What is DML Query Langauge? Data Manipulation Language (DML) - A data manipulation language is a language in which enables users to access or manipulate data as organized throu
What are the ways of obtaining the connection parameters? Hardwire the parameters into the program. Ask for the parameters interactively. Get the parameters
You will be analysing a set of financial data of your choice. It is not necessary to collect any primary data of your own, and publicly available secondary data will be sufficient
Using Literal Character String Example: To print IS A as one string with column name employee SELECT ENAME || ' IS A ' || JOB AS "EMPLOYEE" FROM EMP;
Question: This Question refers to the database schema given in the Appendix. (a) The integrity of a database is enforced by integrity rules. Discuss what should happen on a
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