Linked Questions

17 votes
2 answers
14k views

How to model an entity type that can have different sets of attributes?

I’m having some trouble in recreating a database with a one-to-many (1:M) relationship between Users and Items. This is pretty straightforward, yes; however, each Item belongs to a certain Category (e....
user5613506's user avatar
16 votes
1 answer
7k views

Designing a database for a video game business domain with multiple many-to-many relationships

I am relatively new to database design, and I decided to make my own hypothetical database for practice. However, I am having trouble modeling and normalizing it, as I esteem that there are numerous ...
dpolaristar's user avatar
14 votes
2 answers
24k views

Modelling a database structure for multiple user types and their contact information

I'm designing a database that will store users of varying types. Predominantly (but not exclusively) they will be Actors, Directors and Writers. Currently there are just four user types that are of ...
verism's user avatar
  • 241
11 votes
2 answers
3k 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 ...
MVC Newbie's user avatar
11 votes
2 answers
8k views

What are the practical reasons behind learning relational algebra?

Learning how to formulate query-like expressions in relational algebra is a traditional part of many, perhaps most, "Introduction to Databases" courses. This is usually justified by the assertion ...
Gordon Royle's user avatar
9 votes
2 answers
6k views

Developing a database for a funds transfers business where (a) people and organizations can (b) send and receive money

In the business context of relevance, both members and organizations need to have an account for funds. Funds can be transferred from member to member, from member to organization, from organization ...
aarnes's user avatar
  • 93
9 votes
2 answers
2k views

Advice on a basic design, first time database design

I am taking a course to become a Java developer. The course involves using databases but we never really design any, unfortunately. Most of the time we get pre-made databases and we have to ...
Vahx's user avatar
  • 225
8 votes
1 answer
3k views

Database schema for entities with two possible owner/parent types?

I'm using PostgreSQL with Sequelize as my ORM. I have one type, User. The second type is Group, which can have any number of users associated with it through a GroupMemberships table. Users can also ...
Jakemmarsh's user avatar
7 votes
3 answers
8k views

SQL - Many-to-Many relationship with same table and with relationship constraint

I have a SellerProduct table. Each row within the table represents product information as offered by a seller. The SellerProduct table has the following columns: id (serial, pk) productName (nvarchar(...
user4321's user avatar
  • 215
7 votes
1 answer
2k views

How to model a Letter Transportation business context in a database diagram?

I am trying to crate entity-relationship diagram for a transport company database. This database should store information about letters, deliveries, moving letters from one warehouse to another, and ...
Igor's user avatar
  • 173
5 votes
2 answers
2k views

Best way to linking different entities to a single table

I'm running for office and have created a web app for tracking my door knocks to voters at their homes. The database contains a table called voters that contains all the necessary information about ...
StevieD's user avatar
  • 183
4 votes
1 answer
490 views

Is this a sane model for a network provisioning system?

I'm sketching out a model for a network setup, where I have the following conditions: There are multiple nodes which contains a number of switches each. Each switch has multiple services, which may ...
ChristianF's user avatar
3 votes
1 answer
3k views

Supertypes and subtypes

I am trying to design a database that has supertype/subtypes. I have the following users: - basic user - business user - administrator (super user). All three users share a common table (users) ...
Cristian's user avatar
  • 203
2 votes
2 answers
276 views

Designing a scenario where a primary key could be of two types

I have a table: all_info, where it holds the users identification. The id of this table can be of two types (just one or another, never both), suppose: int and varchar, but one table can't have two ...
Rafael Barros's user avatar
1 vote
2 answers
2k views

How to represent the relationship between artists and albums in an entity-relationship diagram

I'm learning and practicing with the E-R model trying to design a music industry database. With this section of the diagram I have a doubt: I suppose an album can be had by an artist and a band, not ...
dlag's user avatar
  • 17

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