Entity Relationship Diagram

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2
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4answers
65 views

In a one-to-one relationship, where should the foreign key be placed?

I am currently designing an ERD for a project management system. I am unable to choose between two workable solutions as the best solution as I wish to embrace the best standards. The two entities ...
3
votes
2answers
72 views

Survey Database - Respondent Table (1NF or 3NF - Pros and Cons)

Building out a Survey ERD ODS layer. Now i'm debating on the design for my Respondent Table. Not sure if its best to have it as 1NF or 3NF. FOr a quick back story I get a survey extract with ...
5
votes
0answers
59 views

Difference between contains and has in ERD

I am working on an ERD which represents the relationships between entities in a Web development company behavioral model. There I have entities like: Customer Service ----------- (like: web ...
1
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0answers
50 views

ERD Diagram based on Crow's Foot model for Milky Way Jewelry

this was on my final exam this past winter exam season, in search for the answer since i got it wrong: Draw an ERD diagram based on the Crow's Foot model for a database to support the basic ...
1
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0answers
38 views

What is a good database design approach for my Online Quiz Android Application?

I have been working on an Android Online Quiz Application with PHP & MySQL. I know what attributes i need however when designing the relationship it becomes complex and confusing when I analysed ...
0
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0answers
10 views

ERD question, problem with connecting

So I have a question involving an assignment i got. The question is I can see out of a query the total amount of days a room was occupied. However I think my Reservations and Rooms should be many to ...
1
vote
1answer
40 views

ERD to Relational schema

I'm new to DBM and I'm trying to learn it online. Honestly, I need some help with this. I don't know if I'm doing this right, and any help will be appreciated. This is my answer for i.
3
votes
1answer
59 views

Entity Relationship Design; The best scenario

TLDR; What would be the best design choice for the scenario below and how would each design react at extremely large data volume? I have experience working with large government database systems ...
5
votes
2answers
156 views

Dog Adoption Database Design

Apologies if this isn't the norm, but I am seeking advice for the database design for 'dog rescue/adoption'. I've done my normalization research and this is my first attempt at database design. Any ...
1
vote
1answer
38 views

ERD modeling organization and roles

I am trying to model the following scenario: -I have multiple company bureaus. -Each Bureau has multiple offices -Each office has multiple divisions -Each Bureau has employees that only ...
0
votes
2answers
45 views

What is the most efficient way to make a Locality Entity (Town, City, Village etc) with a Country Entity?

I am new to Database. I have a database with a UserProfile Entity. I need to add a Country and Locality(City, Town, Village) to the UserProfile. What is the most efficient way of doing so? This is ...
2
votes
1answer
58 views

Is this table in my ERD redundant? (Image)

I am developing a research article database for a project. My professor approved this design but I feel like the Author's_University table is redundant and that University_ID could just be added to ...
2
votes
2answers
115 views

Best data modeling approch to handle redundant foreign keys in relational model

I am looking for advice on the best relational modeling approach to store surveys, questions, and responses. I am looking for which of the two approaches below looks best, or an alternative approach ...
0
votes
1answer
137 views

Superclass/Subclass Relationship Implementation in MySQL Workbench ERD Diagram

This is a relational model! Trying to figure out how to implement a 1:1 superclass/subclass relationship in the ERD diagram. I'm new to this so I'm not sure whether I have to type out all the ...
4
votes
1answer
190 views

ER vs database schema diagrams

when i search the web for er diagram and database schema these 3 diagram types found but all are named under er diagram.i want to know what is database schema diagram and what is er diagram why all ...
0
votes
1answer
167 views
1
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1answer
33 views

ESports League ERD

I'm creating a database for an esports league and am having some issues putting it all together for an ERD. Here's a quick rundown on how the game works: There are 2 teams of 5 Players each. These ...
1
vote
1answer
70 views

Help me to create correct ER Diagram [closed]

I want to create a database where one user can either be a Doctor or a Patient (but not both). So that, I can get all doctors or patients from doctor or patient table as well as I can search doctor or ...
1
vote
0answers
142 views

Quotation and invoice mysql table

I am trying to develop a small business web application for my friends business. I do have some php,html experience so I have done the interface and all. Now I am trying to work on the database. The ...
0
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0answers
27 views

Normalize to 3NF Question - Postal Codes/City [duplicate]

Normalize to 3NF and design an ERD for the following data: Name Street City Province Postal Code Home Phone Cell Phone Just want to see if I am doing this right. PERSON NameID Name Phone Number ...
2
votes
1answer
62 views

Should I maintain relationships diagrams in the back-end and the front-end?

I’m developing an Access 2010 database application. It is split into a back-end, holding all the tables, and a front-end, holding all the queries, forms, etc. I find the Relationships tool helps ...
4
votes
1answer
293 views

How to enforce a constraint over multiple tables?

I have the following five tables: PRODUCT FEATURE PROVIDER PROVIDER_PRODUCT PROVIDER_FEATURE The logic is as follows: A generic PRODUCT can have one or more FEATUREs. There are different ...
4
votes
1answer
78 views

Do I relate entities that are indirectly related when creating a student-course ERD?

I'm trying to create an ERD for a tutor center, this is what I understood from their operations: There is the tutor center director, then under her there are sections/departments. It, math/calculus, ...
1
vote
2answers
111 views

How to decide when is use ERD or UML for data modeling?

A UML diagram can be used both to model database designs and class designs, but an ER diagram should be used exclusively in database problems. How do you pick one graphical representation over the ...
9
votes
2answers
353 views

Conceptual ERD Multi-table many to many, or possibly recursive?

I'm creating a conceptual diagram [yes, I know I've included attributes and keys - but this is just for me to consolidate what I'm doing whilst learning] -- so please treat it as Conceptual with the ...
2
votes
2answers
139 views

How to review Database schema?

I am green been software engineer, my team lead give me a task in PostgreSQL database, I need to determine the relationship of the all 405 tables, but the problem is the database doesn't have any ...
1
vote
2answers
105 views

Trying to design database for eSports Teams - Issue with dependencies

I am trying to design a database in Access for an eSport league (specifically League of Legends North America). I will post what I have and then explain my issue. My issue comes when I try to ...
0
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0answers
49 views

table design approach for a rental application with several one to many relationships

I'm trying to go about designing a database/tables for the following situation I'm being presented. I'm developing a rental web application with MySQL as db engine. It is for a nonprofit organizations ...
2
votes
1answer
217 views

Bicycle Sharing Scheme - ER Diagram

Please compare the directions below to my ER Diagram and tell me if anything is wrong with my ER Diagram Please I think its accurate enough. Oxford City Council is preparing to launch an innovative ...
0
votes
1answer
52 views

Issue with forming correct relationship between subtype and another table in ERD

The focus is on the Cashier table and the Cash Accountability table. The rule is that only Cashiers have Cash Accountability and a Cashier ideally only cashes out once per day. Before I changed the ER ...
0
votes
1answer
83 views

Database Design / ER Diagram - Help Needed

Please take a look at this ER Diagram that I started. I just don't know if I've set it up correctly (I have not made any relationships yet). I just want to know if I have the appropriate "Tables" or ...
0
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0answers
175 views

ER Diagram Issues

I'm currently working on a project and I just can't figure out how to setup the portion in "BOLD" and any help will be greatly appreciated. Oxford City Council is preparing to launch an innovative ...
0
votes
1answer
108 views

Does my ERD look well designed?

I am making a database at no cost for a local dance school. I'm still very new this would like to be sure that I designed it appropriately. From the front end, the parent will: fill out their ...
1
vote
1answer
103 views

How to get a surrogate key value in order to put a foreign key in and create relationship?

I am trying to create two relationships between three tables, using foreign keys with values of primary keys, which are surrogate keys. But I don't understand how to enter the right value in the ...
0
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2answers
78 views

Does an empty entity make any sense in an entity-relationship diagram?

I have an entity that has nothing else than a surrogate key as a primary key. I use it as an element made of a group of other elements For example : TABLE SchoolClass (classNumber INTEGER ...
0
votes
1answer
149 views

middle table in one-to-many relationships

I just started using mysql workbench but it is slightly from the er diagram that i design in paper. I want to have a 1 to many relationship with three tables. For example a have entity A and entity B ...
0
votes
2answers
49 views

ERD Design for Campground and Campsite

I am designing erd for campground and campsite. In general, a campground has many campsites in it. that lead to one to many relationships. but sometimes campsite has no campground, it appears as the ...
0
votes
1answer
690 views

Is an ER diagram an example of a conceptual, logical or physical schema?

I have been reading databases, and I clearly understand the difference between a conceptual, logical and physical schema. An ER diagram is an example of which of these schema's?
1
vote
1answer
172 views

How to model IsA in an ERD with crow's foot notation

For an assignment I have to create an ERD. I am doing this in Lucidchart using the crow's foot notation. There is however one thing I cannot figure out, how would you present a IsA hierarchy in crow's ...
0
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0answers
22 views

Is the use of my lookup table efficient?

I'm trying to find the best way to architect the relationship in the scenario that: A team can have multiple players, a player may also have multiple teams My first thought was to use a lookup ...
0
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0answers
54 views

ERD to data structure

I'm new to databases. I converted my ERD to data structure. Althougt I made sure all the 1NF, 2NF and 3NF are handled, I'm skeptic about it. This is the data structure. Port(PortID(pk), Name, ...
0
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0answers
21 views

Identification of other entities.

Given the following scenario, what three other entities (and their attributes) would be of importance to this model? SCENARIO: The transport authority in Jamaica has recently added train ...
6
votes
3answers
612 views

Help with a scenario of music groups and members in ERD design

Can someone please show me how to construct this ER diagram with the following scenario? I’m confused with the ‘or’ part of it. Description An Artist has a Name, and must be either a Group or a ...
0
votes
1answer
128 views

How to define User/Permission relationship as M:M?

The Resource relates to Action as M:M via Permission join table/separate entity. User can have many permissions. The same permission may be assigned to multiple users. How to define User-Permission ...
1
vote
2answers
133 views

New to databases - does my ERD reflect good database design?

I'm making a database to hold data for a media player that I'm working on. Originally, I thought to use one table with the fields: {filePath,artist,title,album,track_number,length,date,artworkUrl} ...
0
votes
1answer
49 views

Relationship issue

I'm working on a ERD with mysql workbench, and i have a little question. I have a Database with this tables: company_address country state city I want to store the address of the company with all ...
0
votes
1answer
232 views

What is the best way to represent an album and song entity in an e-commerce schema?

I'm designing a simple mp3(music) ecommerce site, customers can either buy a single Track or whole Album, an Album is made up of Tracks, so there is a one to many relationship between an Album and a ...
2
votes
1answer
49 views

Database table to keep track of objects

I have a table called FoodMaker and another table called Settings. Every FoodMaker has multiple Settings. I also need a 3rd table to record what has been made, when and with what Settings. It might ...
1
vote
1answer
44 views

Financial Inst - Model Role+Relationships b/w Person and Account

A Person can be on one-or-more Accounts. For each Account a Person is on, Person has a certain role on that account i.e. Person 1 is primary on Account 1 Person 1 is joint on Account 2 Person 1 is ...
1
vote
3answers
617 views

Database design: 4 types of users but have different functionality , separate or one table?

I have 4 types of users: Admins , normal user , company , service provider Admins and normal user share some attributes (id .first name ,last name ,phone ,mail) company and service provider share ...