ZuoTi.Pro
Question

How to model this scenario in conceptual ER diagram?Bridge entity needed? I have a house-share entity(...

How to model this scenario in conceptual ER diagram?Bridge entity needed?

I have a house-share entity( primary key : house-share id) and housekeeper entity (primary key: housekeeper id).

At any point in time a housekeeper can only work in one house-share.

When a housekeeper finishes an allocation with a particular house-share the allocation is recorded(start date and end date).

A house-keeper may return to a house-share they previously worked in; if they do so, a new allocation is recorded.

I believe the relationship between house share and housekeeper must be many to many I can come up with a bridge entity(e.g. housekeepingwork)** which have pk's housekeeper id, start_date and end_date. But usually a bridge entity will have primary keys from both entities but not in this case. I'm wondering if I'm modelling this wrong?

engineering   Computer-Science   
0 0
Add a comment Improve this question Transcribed image text
Next > < Previous
Sort answers by oldest

Homework Answers

Answer #1

0 0
Add a comment
Know the answer?
Add Answer to:
How to model this scenario in conceptual ER diagram?Bridge entity needed? I have a house-share entity(...
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Log In

Sign Up

Not the answer you're looking for? Ask your own homework help question. Our experts will answer your question WITHIN MINUTES for Free.
Similar Homework Help Questions

  • Database design Part One (Conceptual Database Design) As a database developer, you have been asked to...

    Database design Part One (Conceptual Database Design) As a database developer, you have been asked to design a new database the operation of the new project within the Liverpool John Moores University (LJMU). LJMU i planning to deliver a number of professional training courses in Al. Each course is delivered by one member of staff at LJMU's Training Centre; each staff is allocated a staff number. The policy of LJMU is to record the start working date of each staff,...

  • c) Write an ER Diagram for the following Library database. Identify all the Entities, Relationships and Attributes. Underline the primary keys and mark the different constraints. You can add an I att...

    c) Write an ER Diagram for the following Library database. Identify all the Entities, Relationships and Attributes. Underline the primary keys and mark the different constraints. You can add an I attribute as a primary key for an entity to make t unique if necessary. Library has a number of branches in the city, each branch having a name, address and librarian. Books have title, authors and publisher. A book can have multiple authors but a single publisher. Note that same...

  • Q1.a) Based on the business rules, you are expected to construct an Entity-Relationship (ER) diagram. The...

    Q1.a) Based on the business rules, you are expected to construct an Entity-Relationship (ER) diagram. The ER diagram should include entities, attributes (if there are less than three specified in the business statements, please add some extra attributes), identifiers and corresponding data types, the relationships among entities with cardinality and associative entities. .b) Extend Q1.a) to apply generalization/specialization technique to construct an Enhanced-ER (EER) diagram. The EER diagram should specify the complete (total) and disjoint (mutuallyexclusive) constraints on the generalization/specialization....

  • 1) Create Conceptual Schema Diagram 2) Create a fully attributed Loagical Data Model Diagram 3) Create...

    1) Create Conceptual Schema Diagram 2) Create a fully attributed Loagical Data Model Diagram 3) Create the SQL script that will generate the data model Develop an EER model for the following situation using the traditional EER notation, the Visio notation, or the subtypes inside supertypes notation, as specified by your instructor: Wally Los Gatos and his partner Henry Chordate have formed a new limited partnership, Fin and Finicky Security Consultants. Fin and Finicky consults with corporations to determine their...

  • I need help. Valley Vineyard Conceptual Model Case Read the case then create an entity-relationship diagram...

    I need help. Valley Vineyard Conceptual Model Case Read the case then create an entity-relationship diagram that captures the essence of the problem domain. Identify the entities (diagrammed in a rectangle box) Establish and label the relationships (diagrammed in a diamond) Determine the cardinalities Add the attributes, if you diagram is too busy the attributes can be on a separate page. Be sure to note any assumptions you have made. CASE: Valley Vineyard’s customers are mainly restaurants and wine shops...

  • ER Modeling: Assignment In order to receive credit for this assignment, you must draw your ER...

    ER Modeling: Assignment In order to receive credit for this assignment, you must draw your ER model using a compute program and then turn in on the blackboard. Your ER model should include all of the necessary entity sets, relationships and keys, as well a weak entities and superclass/subclass relationships, if needed. A company decides to implement a software to monitor its employees' web surfing, and stores history of each employee's surfing in a database, as well as all of...

ADVERTISEMENT
Free Homework Help App
Download From Google Play
Scan Your Homework
to Get Instant Free Answers
Need Online Homework Help?
Ask a Question
Get Answers For Free
Most questions answered within 3 hours.
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT