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!
Explain the concept of QBE?
Query-by-example represents a visual/graphical approach for accessing information in a database by the use of query templates called as skeleton tables. It is used through entering example values directly within a query template to represent what is to be achieved. QBE was developed at IBMs. T.J. Watson Research Centre and it is used through many database systems for personal computers. QBE is an extremely powerful facility that gives the user the capability to access the information a user needs without the knowledge of any programming language.
Queries in QBE are expressed through skeleton tables. QBE has two distinct features:
- QBE has two-dimensional syntax: Queries look like tables.- QBE queries are expressed "by example". Instead of giving a process for obtaining the desired answer, the user provides an example of what is desired.An example of QBE is given asEMPNO NAME SALARY DESIG DEPTNO P..x "Manager"
This query tells the system to such as for tuples in EMP relation which have designation Manager. For each such tuple, the system assigns the value of the Ename attribute to the variable x and prints it.
What are the disadvantages of file-processing system? Ans: The Disadvantages of File-Processing System a. Data redundancy and inconsistency - Data redundancy means not nece
List any eight applications of DBMS. a) Universities b) Airlines c) Banking d) Credit card transactions e) Tele communication f) Sales g)Finance h) Manufac
When is a transaction rolled back? Any changes that the aborted transaction made to the database must be uncompleted. While the changes caused by an aborted transaction have be
When are they useful? Justify with an example. The temporary tables are commonly used to support specialized rollups or exact application processing needs. Unlike a permanent t
. Ashutosh Dubey who is the director of Gyan Gurukul want a three-level schema architecture for the Gyan Gurukul Company that provide better security also design a data abstraction
real life situations where database management system are most suitable
Explain forms based and graphical interface? Forms based and graphical interface: graphical user interface (GUI) is a kind of user interface which permits people to interact
A software contract and consultancy firm maintains details of all the various projects in which its employees are currently involved. These details comprise: Employee Numbe
er diagtram for icici
Explain natural join? Natural Join - Similar as equi-join except in which the join attributes (having similar names) are not involved in the resulting relation. Only one sets
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