Question

2. Consider the following application description for a publishing firm, and translate all of the information as precisely as possible into an ER diagram. Make sure that your diagram is unambiguous; e.g., that the TA can tell the difference between a double line and a single line. Clearly explain which (if any) information cannot be represented in the diagram. If you need to make any assumptions, state them clearly.

A publisher publishes two kinds of publication: books and magazines. Books have an ISBN number, title, price, and one or more authors. Magazines have an ISSN-number, title, volume-number, newsstand-price, subscription-price, and one or more editors. One of the editors is designated as the editor-in-chief. Editors may edit multiple magazines, but an editor may be editor-in-chief of at most one magazine. Each magazine contains a number of articles. Each article has a title, a starting page number, and one or more authors. A publication may be involved in an advertising campaign. While a publication may be involved in multiple campaigns, a campaign covers just a single publication. A campaign has a budget, a theme, and a manager.

Answer 1

Refer the Image and read the explainatiob simultaneously

1. First see the image conatining representation of different blocks i.e rectangle, diamond , ovals etc.

2. Key Attribute is used to uniquely distinguish a row of data from other rows

3. Multi-Value attribiute means that it can have multiple values for same attribute

REPRESENTATION

ER DIAGRAM

Now see the ER DIAGRAM and take one by one line of the question

1.A publisher publishes books and magazine so take a entity as publisher and relationship between them is publish

so a diamond of publish linked to books and magazine entities.

2. Books have various Attributes so draw each attribute in a oval so here attributes are ISBN Number (which is key attribute ) , Title, Price , Authors (where author is a multi- valued attribute as it is said in the question one book can have many authors so represented by double oval)

3.Similarly for magazine also we have many attributes ISSN No (key attribute). Title.Volume No.Subscription price And editors (as multi-valued attribute) .

4. Now we talk about relationship between magazine and editors .

As question says that one magazine can be edited by mpore than one editors so relationship i.e edits between magazine and editors is 1:M relationship (refer image of how to show 1:M mapping ) .

5. As only one editor can be designated as Editor In chief so they both are related by 1:1 Mapping (refer image of how to show 1:1 mapping )

6 . Next part of problem is that each magazine contains many articles so relate both Magazine and Articles by 1:M mapping as shown in ER diagram (On left side of the page )

7. As Article aslo have many attributes so represent all using oval as title, starting page no. , Authors(multi-valued attributes as question says one article can have many authors )

8 . This ends Up the ER Diagram For the problem

ASSUMPTIONS

1. Taken ISBN NUMBER as key attribute of Books entity

2. Taken ISSN NUMBER as key attribute of Magazine entity

3. Taken two extra attribute for Editors as eid and name where eid is the key attribute .

Note

Now rest part of the where it is saying about publications and advertising campaign.so this part is not realated in any way with the above ER Diagram so it cannot be represented in the diagram.

As publishion and avertising campaign are related with each other but not with Books or magazine or articles or editors or editor in chief or publisher so we cannot give a relatioship between any entity with the publications .

It is having No relationships with any other entity in the diagram .

Thank You

I hope that It helps you so If you like the answer please Upvote