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!
What is aggregate function? Briefly describe it?
Aggregate functions are functions that take a collection of values as input and return a one value. SQL offers 5 built-in aggregate functions:
a) Average: avg
b) Minimum:min
c) Maximum: max
d) Total:sum
e) Count:count
Average: avg
Select avg (balance)
From account
Where branch-name='perryridge'
Count :count
Select branch-name,count(distinct customer-name)
From depositior,account
Where depositor.account-number=account.account-number
groupby branch-name
Explain Record Based Logical Models? Record-Based logical Models: Also define data at the conceptual and view levels. Unlike object-oriented models, are used to state overall
Explain Candidate key? Candidate Key - A candidate key is a minimal superkey, that can be used to uniquely identify a tuple in the relation.
Question : Object-Oriented Database (OODM) is defined as a logical data model that captures the semantics of objects supported in object-oriented programming. An Object-Oriente
as a customer service employee, explain five measures you would recommend a displeased student to patronise a school canteen
Define the notation for classes and atrributes The notation for class, attribute, and operations are shown below: Figure: Class with attributes and operations A
Describe the nested-loop join and block-nested loop join. Ans: The block nested- loop join algorithm is as described below: for every block B r of relation R do beg
Cardinality of Relationship One-to-One Only one entity of the first set is linked to only one entity of the second set. E.g. A teacher teaches a student. Only one teacher
What is NULL? Give an example to described testing for NULL in SQL? The NULL SQL keyword is used to represent either a missing value or a value which is not applicable in a re
Type of views : Simple views and Difficult Views Feature Simple Views Complex Views Number of tables One
Q. Define a weak entity set and its identifying relationship. List the necessary conditions for a meaningful identifying relationship set of a weak entity set. Entity is a t
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