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

Participation constraints, The participation Constraints shows whether the ...

The participation Constraints shows whether the existence of an entity depends on its being associated to another entity by the relationship type. There are two kinds of participat

Explain the integrity constraints, Explain the integrity constraints: Not N...

Explain the integrity constraints: Not Null,  Unique, Primary Key with an example each. Is the combination 'Not Null, Primary Key' a valid combination. Justify. Not Null - Shou

Prepare an erd for the scenario, Question: (a) Prepare an ERD for the s...

Question: (a) Prepare an ERD for the scenario given below. (b) Convert the ER diagram produced in (a) above into its physical design. You have to choose an appropriate Pri

Explain the functions of data manager, Explain the functions of data manage...

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

Help, #questiononsider the following relation: CAR_SALE =(CAR_ID,oPTION_TYP...

#questiononsider the following relation: CAR_SALE =(CAR_ID,oPTION_TYPE, Option_listpreice, Sale_date, Option_discountedprice)..

What is conceptual schema, What is conceptual schema? The schemas at th...

What is conceptual schema? The schemas at the view level are known as subschema that describe dissimilar views of the database.

Central database schema, Consider an information system designed for an onl...

Consider an information system designed for an online company which provides IT products and services. These include desktops, laptops, networking products, IT books, parts, and te

Perform an exploratory analysis on the entire dataset, Australian Bureau of...

Australian Bureau of Statistics (ABS) provides retail data for different groups and different states as well as the aggregate numbers. Table 11 " Retail Turnover, State by Industry

Discuss the problem of spurious tuples, Discuss the problem of Spurious tup...

Discuss the problem of Spurious tuples and how we may prevent it.    Ans:  A spurious tuple is, mainly, a record in a database that gets created while two tables are joined bad

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