Entity Relationship Diagram
1
vote
1answer
34 views
Multi-variance products
My current system houses different variants of Products in different tables;
Productgroups
Productcolors
Productsizes
Productmodels
Products can reside under 1 Productgroup and can have ...
0
votes
0answers
20 views
ERD diagram may or may not statement
I am getting ready for college exam and one of the questions for ERD is to represent:
A newspaper advertises many properties and a property may or may not be advertised in a number of newspapers.
...
1
vote
2answers
217 views
Refactoring/normalization - but almost empty table
I normalized a legacy DB into this structure:
But I'm not sure if it is correctly normalized. I don't feel very comfortable with the almost empty filters table.
The requirements
A group contains ...
0
votes
0answers
48 views
Designing ERD1 and ERD2 with crows foot [closed]
What would be the perfect ERD1 & ERD2 for the following case study? And what are the attributes of the entities?
Five Aside Football Independent League (FAFIL)
The Five Aside Football ...
0
votes
2answers
97 views
ERD Review Please
I am building a simple database driven web application, but from reading so many books on the subject, I know that if my database is messed up, then my application too, will most likely be messed up.
...
0
votes
0answers
63 views
New to Database Design. Need to create an ERD [closed]
I'm developing a website and need to create an ERD for the website. I've never created one before but will be using MySQL to design it once I figure out the tables necessary. All I am asking for is ...
1
vote
1answer
155 views
Payment methods conceptual and logical model
I need to create a conceptual and logical (normalized) models of parking house according to the requirements below. It looks to me as a very simple concept that doesn't need all tables to have ...
1
vote
3answers
193 views
Software tool to visualize and print DB diagrams
I have some SQL Server databases and use SQL Server Management Studio to manage them.
However, I find that is not very friendly to create, design and print database diagrams (for existing tables).
...
1
vote
1answer
347 views
How to model entities in an entity relationship diagram?
I'm a beginner Database designer and wondering if anyone can help me understand this.
Let's say we want to design a system that has, among other entities, an entity called Vehicle, and another one ...
4
votes
2answers
287 views
Are there any tools to go from ERD to DB design and vice versa?
I'm learning DB design and looking for some tools, preferably open source software, that could help go from an ERD to a DATABASE and vice versa.
For the record, the database i'm using is MySQL.
0
votes
1answer
127 views
Users database to store access levels, can I move the non-essential information to another table?
I would like some advice on the best database structure for my system.
I have different kinds of users with different access levels, and different information of course. I created a users table with ...
4
votes
1answer
1k views
Modelling Relationships in an E-R Diagram, Table or Foreign Key?
Should a relationship in an E-R diagram be created in the database as a table or a foreign key?
For example:
a tutor lectures a class
I see it as three possibilities:
there is a "lectures" ...
4
votes
1answer
184 views
How are indexes represented in an ERD?
What do indexes look like in an Entity Relationship Diagram?
I've googled it and I'm unsure what the standard look of an index is in an ERD. And I'm talking about the crowsfoot diagram that includes ...
0
votes
1answer
420 views
How do I persist recurring events?
I've been tasked with designing a system to recur events. Events may recur daily, hourly, monthly or yearly. Users should be able to schedule events "every 3rd Wednesday of the month" or "The 1st of ...
2
votes
2answers
159 views
How do I create a user invitation model?
I am developing an application which allows 'users' to create 'lists'. I have a many-to-many relationship between 'users' and 'lists' (this might not be right). Additionally 'Lists' have many 'Tasks'. ...
8
votes
1answer
357 views
How do you represent VIEWS in an ERD?
Are VIEWS (CREATE VIEW) represented in an ERD? If so, how do you represent them and specify what tables they came from?
3
votes
2answers
796 views
Tool for Reverse Engineering of PostgreSQL Database on Linux (Ubuntu)
Please suggest a tool to reverse engineer a PostgreSQL DB into an entity-relationship-diagram (ERD) or equivalent ??
Ideally, I'm looking for a simple ERD or UML class diagram in a format that is ...
0
votes
0answers
629 views
Generating an ER diagram with relationships from an MySQL MyISAM database?
Are they any tools to extract out the relationships in a MyISAM database into an ER diagram?
I understand that MyISAM doesn't have foreign keys, but the columns in my database that represent foreign ...
2
votes
0answers
248 views
How to translate high level entity relationship into schema
According to the following articles written by Dr. Chan, we can describe high level entity relationship. (see page-10,11 of doc-A and page9 of doc-B)
•doc-A) English Sentence Structure and ...
0
votes
0answers
491 views
ER to Relational Schema [closed]
I have developed an ERD diagram with UML notation in StarUML.
Now, I need to draw a relational schema but due to lack of features in StarUML i must use other tool.
My question is what exactly goes ...
2
votes
1answer
118 views
1
vote
1answer
148 views
Guidance on simplifying the following diagram
I have a case scenario where a customer can book accommodation or flight only or both.
I have modeled the accommodation part, however i am making things complex by over-thinking how stuff works in ...
2
votes
1answer
142 views
How can i model this data
A customer can make a reservation for an accommodation, the accommodation can be in a resort or elsewhere.
So i would say that a resort can have different types of accommodations, ie. Chalets, ...
1
vote
0answers
181 views
Entity relationship diagram
What is the difference between ERD 1 and ERD 2?
From what I understand is that ERD 2 has the many to many relationships resolved with a link entity whereas ERD 1 only shows the relationship... is ...
3
votes
5answers
8k views
How to export an ER diagram from an Oracle DB?
I am developing this application with an Oracle database. I haven't been documenting the data model, but now an auditor wants to have an entity relationship diagram of my database. There are many ...
5
votes
3answers
434 views
how do I model this in database?
I am using mysql as my backend database. Here is the use case;
A HolidayPackage is configured with some default offerings. These default offerings can be up/downgraded based on the options provided. ...
1
vote
0answers
145 views
Entity relationship modelling, comment on my ERD
Note: Due to low reputation I can't post images so i have added the links accordingly.
I have this assignment I'm working and I am stuck in a recursive relationship, following is part of the case ...
1
vote
1answer
202 views
Suggest good ERD tool with UML notation
I need to design an ERD with UML notation, can anyone recommend a tool that does this.
1
vote
1answer
162 views
ERDs: How do you indicate mutually-exclusive encounters?
If you have a character_instance and character entity in an ERD for a video game, and you want to indicate that something happens when a character entity encounters a character_instance entity, how do ...
5
votes
2answers
180 views
Design: How do you decide when items are related vs when they are attributes?
I've been trying to figure this out for a while. Let's say you have a person, for example. An attribute of a person is his or her social security number, right? But a person also has a social ...
3
votes
1answer
871 views
ERD via Chen's notation: How do I organize multiple 'last done' entries?
I'm having an issue creating a little practice ERD. I'm trying to do some more difficult stuff, and I'm not sure what the standard way to organize it is.
Basically, I don't know which of these is ...
5
votes
5answers
2k views
Importance of ER Diagrams
I am a student and I am developing several projects as a part of my academia.
While developing the database for one of the projects, we came across a situation where we thought about whether ERD is ...
1
vote
1answer
321 views
Exporting from SQL Server 2005 for import into ER Studio 9.0
I am new to ER Studio and need to create an ERD for a remote system. That system can only be accessed by LogMeIn remote control and by FTP. The remote system is running SQL Server 2005. The local ...
1
vote
1answer
209 views
Query regarding normalization of the relations
I am given a case study of Event Management to develop an ER model and based on it its normalization forms and relational schema. Now i have developed my ER Model based on the SRS that i have ...
2
votes
2answers
924 views
Is it OK to have an entity in an ER diagram without a relationship?
I'm creating an ER diagram for a class assignment and I was wondering if it would be possible to create an entity that had no direct relationship to any other entity, and simply use foreign keys to ...
3
votes
1answer
5k views
How can I import the contents of an Oracle database into Visio to create an Entity Relationship Diagram?
I have an Oracle database, and I would like to create an ERD in Visio 2007 Pro.
I have so far looked at DBMS_METADATA.GET_DDL commands to generate ddl. I know that I can import an Access DB into ...
5
votes
2answers
520 views
How to structure a model to properly and efficiently represent tree-like data on relational databases?
Based on Traversing tree-like data in a relational database using SQL question, I would like to know how the way regularly used to describe tree-like data on relational databases considering physical ...
20
votes
10answers
539 views
What is an effective way of labeling columns in a database?
I used to label columns in my databases like this:
user_id
user_name
user_password_hash
To avoid conflicts when joining two tables, but then I learnt some more on how to alias tables, and I stopped ...
