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.
We want have a website; we need to test the security of our website. You need to: -Try to bypass our security by simulate a website hacking -Try some hack Techniques like
For the relations answer the following queries in SQL Street (name, location, city) House (number, street_name) Lives (name, house_number) (i) Obtain the names of persons who liv
how the string works as keyword?
Advantages of Observation Methods: Bailey has pointed out four advantages of observation: 1. Superior in Data Collection on Non Verbal Behavior: When a person a opi
find a name whose address is erode from student table
Mention various steps required to draw an E-R Diagram. Draw an E-R Diagram for Student Information System. Mention all suitable assumptions to justify your answer.
Explain the functions of data manager? Functions of Data Manager : - Convert operations in user's queries coming directly through query processor or indirectly in an applicatio
Explain the Cartesian product: The Cartesian product operation does not need relations to union-compatible. The meaning of this is that the involved relations may have dissim
Design a gennalization and specialization hierarchy for an automobile sales company
Express the properties of Strings? Strings can be case sensitive (or not) which can change the outcome of string operations. You can evaluate whole strings \ just part
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