Explain weak and strong entity type, Database Management System

Assignment Help:

Explain weak and strong entity type ?

Weak and Strong entity type: An entity set which does not have a primary key is referred to as a weak entity set. The existence of a weak entity set depends on the existence of a strong entity set; it must associate to the strong set via a on-to-many relationship set. A discriminator of a weak entity set is the set of attributes that distinguishes between all the entities of a weak entity set. The primary key of a weak entity set is formed by the primary key of the strong entity set on that the weak entity set is existence depends, plus the weak entity set's discriminator.


Related Discussions:- Explain weak and strong entity type

Discuss difference between drop table r and delete from r, Discuss The diff...

Discuss The difference between drop table R and delete from R.  DROP TABLE command deletes all the records with the table definition. This command will automatically committed

Produce a logical database design for pharma, Using a database design appro...

Using a database design approach of your choice, produce a logical design for Pharma. 1) Your answer must consist of ONE the following: An entity-relationship (ER) diagra

How many levels can be viewed architecture of the database, How many levels...

How many levels can be viewed in Architecture of the database ? Architecture of the database can be viewed as three levels.

What are composite objects, What are composite objects? Objects that ha...

What are composite objects? Objects that have other objects are known as complex objects or composite objects.

What is a merge sort, QUESTION (a) Using an appropriate example, explai...

QUESTION (a) Using an appropriate example, explain what is a recursive function? (b) Explain in detail the C++ function given below. void search2(int list[],int n,int ele

Write query to select student from math department, Consider the table stud...

Consider the table student and list names of students in the departments other than maths and computer. SELECT std_name FRM student WHERE dept_name NOT IN (‘Maths','Computer);

Define the notation for classes and atrributes, Define the notation for cla...

Define the notation for classes and atrributes The notation for class, attribute, and operations are shown below:     Figure: Class with attributes and operations A

Sub query in the update command, Sub query in the UPDATE command : Exam...

Sub query in the UPDATE command : Example :  //Double  the  commission  for  employees,  who  have  got  at  least  2 increments. UPDATE EMP SET COMM = COMM * 2 WHERE

What are the uses of odbc, What are the uses of ODBC? Under what circumstan...

What are the uses of ODBC? Under what circumstances we use this technology? ODBC expose database capabilities within a standardized way to the application programmer by an ap

File organisation in dbms, File Organisation In Dbms Introduction ...

File Organisation In Dbms Introduction Databases are used to store information. Usually, the principal operations we have to perform on database are those relating to:

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

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!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd