Questions tagged [database-diagrams]

The tag has no usage guidance.

35 questions with no upvoted or accepted answers
Filter by
Sorted by
Tagged with
5
votes
1answer
2k views

ERD for a web development company

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 ...
3
votes
0answers
33 views

How to design a database for my entity-relationship diagram about Projects, Tasks and Developers

I'm new to database and my entity-relationship diagram is as follows: According to that I designed my SQL-DDL database statements as shown below: CREATE TABLE Developer ( DeveloperID int NOT ...
3
votes
0answers
797 views

ERD for a Contract between a Writer and a Publisher: Is it correct, can it be simpler?

I created an entity-relationship diagram (ERD) for a book publishing business context that I will detail bellow. Entity types The entity types of interest are: Writer Work (as a book) Publisher ...
2
votes
0answers
33 views

Variable layers of data in a multi-country addresses system

My diagram I want to record addresses in my database. The layout I have right now is visible in the diagram below: Considerations Continent, Country, Subdivision and City will be pre-filled, ...
2
votes
0answers
178 views

Modelling a database for a simple IT device tracking scenario

Sorry, my English is not that good. I need a simple IT device tracking sytem at work. For each device I need to know its current location, status and ownership (employee to which it is assigned). ...
2
votes
0answers
95 views

How can you use an entity-relationship diagram to document business processes?

Past exam question: How can you use an entity relationship diagram to document business processes? As far as I know, I would use an entity-relationship diagram (ERD) to document the relationships ...
2
votes
0answers
527 views

What is the difference between (Superclass/Subclass) Total and Partial Specialization?

What is the difference between total and partial specialization of superclass/subclass (or supertype-subtype) structures in enhanced entity-relationship modeling?
1
vote
0answers
40 views

Room bookings database - does it make sense to create two tables instead of one column?

There are two types of entities: user and room. A user can book room select room unbook room unselect room "Selected room" is a state that indicates when a user has decided to book a room and so he/...
1
vote
0answers
287 views

Crow's foot notation--what is the difference between “one” and “one-and-only-one” regarding relationship cardinalities?

I'm trying to figure out the difference between the single-bar and double-bar cardinality indicators as in the figure below: Some sources seem to use one notation while others use the other. I can't ...
1
vote
0answers
384 views

Gaming shop database schema

I'm trying to design schema for my personal project that would be an online gaming shop. I would like to ask you guys for any suggestions/tips on how could I maybe improve my current draft. Concerns: ...
1
vote
0answers
186 views

Modelling an entity-relationship diagram for a scenario involving companies, services, and clients

I am creating an entity-relationship diagram (ERD) for managing workflow and other details of Company X in which I am maintaining details of the following objects: Employees of Company X Services ...
1
vote
0answers
60 views

Creating an entity-relationship diagram about an art fairs and galleries business environment

Scenario description The charactheristics of the business domain under consideration are: Each and every art item has a unique identifying number, and also a name and asking price. Art galleries ...
1
vote
0answers
236 views

Basic ERD analysis for a martial arts business domain

I am working on a basic website in order to support querying results from martial arts tournament data. We use participation data to determine things like who gets to host tournaments, regional awards,...
1
vote
0answers
31 views

PostgreSQL table relationship clarification

I am in the process of setting up table relationships, using a relational diagram provided by our vendor, in PostgreSQL 9.5.3 and am seeking clarification on how to relate a child table that serves ...
1
vote
0answers
248 views

ER Diagram - Choose One or Both of the Entities

So I am attempting to create an ER Digram for a certain catering service. Two of the entities are "Lunch Menu" and "Dinner Menu". Each catering reservation (entity) must contain either one of the two, ...
1
vote
0answers
146 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
vote
0answers
576 views

MySQL Workbench Forward Engineer from only the current diagram

I want to create a test database from a huge schema in MySQL, but when I try to do Forward Engineer from a Diagram with about 6 tables, it try to create all the tables, views and routines groups that ...
1
vote
1answer
181 views

How to create a correct entity-relationship diagram (ERD) about a video game profits scenario

I'm starting to build my application database, and I'm really new to the this world, so I have a lot of doubts about my ERD and if its entity types and relationships are ok. This is an application ...
1
vote
2answers
3k views

Crow's Foot notation and identifying -vs- non-identifying relationships

Is it possible to distinguish between identifying and non-identifying relationships using the Crow's Foot notation? Case in point: In table Book, part of the book's Primary Key is a FK to the Author ...
0
votes
1answer
22 views

Need help to design ER diagram

I need to design an ER diagram for a centralized healthcare management system for my college mini-project. Firstly, I came up with the following ER diagram. ER-diagram-1 While designing the tables ...
0
votes
0answers
12 views

2 Relationships between same 2 entities

New database student here. I am having troubles understanding this case for ER to relational database conversion. So when mapping this to a database does the table for entity one look like this? ...
0
votes
0answers
51 views

Modelling Orders and Messages for an e-Commerce database

In my e-commerce application I would like that buyers and sellers interact via a messaging system to purchase products. The process consists of: The buyer inquiring for a product The seller responds ...
0
votes
1answer
27 views

Is there a place to store ERDs in Postgres?

Is there a designated spot in Postgres to store Entity-Relationship Diagrams (ERDs)? I could just create a table with a BTYEA column or something, but I want to make sure to use what exists if ...
0
votes
0answers
22 views

Relationship constrains in EER

When designing a EER diagram, how do you state or show a specific relationship constraint between entities (or can this even be done). We have a relationship between two entities E and F, but for a ...
0
votes
0answers
157 views

Multiple tables for different types of transactions?

Considering a trading system as an example. Would it make sense to have two different tables for credit transactions and asset transactions? creditTrans : table id userId transType status amount ...
0
votes
1answer
204 views

How to maintain customer addresses for Orders?

The database I am designing is part of a project I am working on. I have come up with 3 simple "business rules": Customers must either be Individuals or Businesses (a business belongs to a certain ...
0
votes
2answers
59 views

payment table in relational datase

I have to model a database table for payments. These need to have two fields payment from and payment to and this needs to link to two tables one is clientA and clientB as in the representation below. ...
0
votes
0answers
59 views

Issue with diagrams in sql management studio 2014

I have this issue with sql management studio 2014. When creating a new database diagram and when I add existing table to a new diagram, the data inside a table is obsolete. I tried both dragging a ...
0
votes
0answers
605 views

In an ER diagram, do all entities need to be connected?

I am building a model DB of an online store. I have obvious tables such as Customers, Stores, Products, etc... I made an ER diagram, but I realized that my Employees table is sitting out by itself ...
0
votes
1answer
2k views

I Need Help With My Database Design for Product Management

I'm designing a MySQL database and the front end for my work. The database will store all of the products that we sell on our marketplaces and their relevant data. We will be able to lookup products ...
0
votes
0answers
29 views

Database diagrams & DENY on tables/schemas

So, my developers want to be able to create database diagrams in the dev database, which is fine. And I want to DENY them access to selective schemas and tables which are deprecated, so that I can ...
0
votes
0answers
203 views

ER diagram to tables

Consider the following exam question: Translation: The INCORRECT transformation from the diagram at the right to tables is... This is what I think: a) is incorrect (the column es_C (is_C) does not ...
0
votes
0answers
4k views

Generating an ER Diagram from SQL CREATE TABLE statements

As I can't find any ER diagram feature built in with Apex, I want to create one with the SQL statements I executed in order to set up the tables in my Apex Workbench. I found schemaSpy, which is ...
0
votes
0answers
328 views

Need advice on this EER Diagram

This db will work with a CakePhp app and need advice about design. Is it good idea to put orders on center or should I put clients on center? Clients has orders and an order record can only have one ...
-1
votes
0answers
28 views

What do these ERD relationship arrows mean practically? (One to one, zero or one to one)

So let's say we have this situation: I know this means that foreign key fk1 can be assigned to only one primary key id2 and likewise (meaning there cannot be duplicates of fk1 values in table1 as far ...