Questions tagged [database-diagrams]

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Chen notation to crow's foot

How do I illustrate relationships which has an attribute in chen notation to crows foot notation? Example: There is an attribute "quantity" in the relation. How do I draw that in crow's ...
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Is this ER diagram correct?

I am working on my first ER diagram, for a clothing brand case study. I was wondering if my work is correct. Any feedback is more than welcome. My most important concern is the key relationships ...
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Entity relation with itself

I want to make an ER diagram for scientific research papers, one of the constraints is that a paper shouldn't cite itself. I'm not very sure how to achieve this, as this question points out, the ER ...
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1 answer
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Database Design For Realty Website Review

I am designing a real estate website and wanted feedback from some professionals about the database schema that I came up with. I created a property table that would have each house. Each house can be ...
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Is it possible for a weak entity to be related to its identifying strong entity, as well as another non-identifying strong entity?

For context, I and a small group aim to design a game recommendation/search engine, and we ran into some problems designing the ER Diagram & translating said diagram into relational schema. At ...
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ER Diagram Aggregate relationship

Recently I started working on a class project where we are required to make a DBMS that models a game recommendation engine. We just got the ER diagram started, & I ended up making an aggregate ...
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How to re-design my relational model if there will be NULLs in one column?

I'm trying to build database which allow me store job postings from scraped websites and now I'm in phase of creating a relational model. Getting straight to the point I want to know how should I re-...
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Do I need to implement id column to table if i know that every added row will be unique? [duplicate]

I want to create database which allow me to store IT job offers from various websites. While creating ER diagram I started wondering if I really need an id column in one particular table. Look at this ...
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Need feedback on my ER diagram

I want to create a database which allow me to store IT job offers scraped from several various websites. The problem is that job offers from these websites are not described in the same consistent ...
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1 answer
277 views

what is best way to handle history tables in postgresql?

I am working on the following database structure/diagram for an app using postgresql 13 server Is there a better way to design these table relationships with the tables subscriptions_history and ...
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How do I produce the relationship diagram in Microsoft Sql Server?

How do I produce the relationship diagram in Microsoft Sql Server? Here is a visual of what I am talking about here:
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Question for my entity relationships

I'm not sure how I should think regarding my database design. I have made this database schema below. And I'm trying to think about the relationship between the entities. I have read through online ...
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Meaning of inverted vs non-inverted ISA triangle in EER diagram

I found two different ISA triangles in various books. Like one is inverted triangle(in first figure) and another is non-inverted triangle(as in second figure). Are they give the same meanings? I am ...
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DB relationships with historical tables review

Idea is simple. User -> Projects -> Sprints -> Tasks, but I need to keep historical versions for them. It will fit to my requirements or there are some changes to be applied? - or different ...
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Database ER diagram review. Is this a good database design ? [HELP]

This database For school management system. Please review and help me with your ideas.
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How can I categorize entites by their age in an entity relational diagram?

I am designing an entity relational diagram and I need to categorize entities in groups by their age. What I have is an entity of Person and some personal attributes about it. But I want to have ...
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Designing User & its Sub User Database Diagram Problem [duplicate]

There are some business category e.g. Travel Agency, Hotel, Car Rental etc. Roles: Management rolesSuper Admin, Staff Customer side roles are Owner, admin and sales counter May be etc. customer side ...
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Is Star/Snowflake database design good for applications? What is the alternative?

I need to solve an exercise for a pharmaceutical company, they ask me to create a database structure from scratch given a few informations. Because I want it to be scalable and "future proof"...
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1 answer
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Is my way of creating a entity relationship diagram correct?

From what I understand, 1)table customer and table order should have a one to many relationship since customer has orders. 2)table order and table payment should have a one to many relationship since ...
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Table Diagram and Access File of Contact Database for Church

I have volunteered to design and develop an MS Access database for contacts at my local church in Jamaica, which has no budget to hire a database expert. I have attempted to design a database for the ...
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ER Diagram | Group, Post, User relationship

I need to design an ER diagram, but I am confused in a section, more specifically how to relate the post with the groups, because I need that post contains the information of in which group I publish ...
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How to represent foreign key in an Extended ER Model in Chen notation?

This is a spin-off of the question at How to represent foreign key in an ER diagram? which is too vague about the needed notation. There the idea of underlining FKs with a dotted line is stated. I ...
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How is this E-R diagram of an identifying relationship's mapping cardinality correct?

According to textbook Database System Concepts,"The identifying relationship is many-to-one from the weak entity set to the identifying entity set, and the participation of the weak entity set in ...
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Chat/conversation history, entity relationship diagram

Totally aware that there are very similar questions, went through each of them, but those are pretty simple/basic solutions from where i took some things and ideas to create below entity relationship ...
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Database ER diagram review. Is this a good database design?

I have a task to design an ER diagram and task is given as points below is the description of the problem: A telecommunications company employs thousands of consultants. Each consultant is assigned ...
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How can I create a database diagram, showing clearly the FK and PK in SQL Studio 2016?

I would like to know the best way to create a database structure diagram, that shows relationships between certain tables. I am using SSMS 2016. I tried using "database diagram" option in the SSMS ...
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What is the Relationship between Instagram users and user followers

I'm building a blog project, which each user can follow other users. I'm still figuring out the design and creating the diagrams first. I know that the relationship between users and followers is many ...
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Carry forwarding token wallet concept [closed]

I'm trying to create a carry-forward wallet system. Recharge part I'm developing an app that has the carry forwarding token wallet concept. However, when an user recharge their wallet, an amount of ...
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2 votes
1 answer
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Database diagram for linked server tables

I run Microsoft SQL Server Express 64-bit version 14.0.2027.2 (X64) on Windows 10 Pro 10. I created a linked server connecting tables from a Microsoft Access (mdb) database to Server Objects/Linked ...
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2 votes
1 answer
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ER Diagram Design: Should every entity have a primary key? And can we have sub entity? [closed]

Problem: Design a ER diagram such as: An item has the attribute: description. An item can be sold by a company or a person. A person has the attributes: name, phone and email. A company has the ...
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1 vote
1 answer
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The best practice for SQL + NoSQL database design [closed]

I’m in process of designing database architecture for my diploma project and I have second thoughts about different solutions. I know and understand all my objectives can be done within relational ...
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1 answer
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Is it possible to generate DB diagram for all SQL databases opened in SSMS

At the present we have to go to each database and manually generate database diagrams, so I want a way to automate this. Question: Is it possible to generate DB diagram for all SQL databases opened ...
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2 votes
0 answers
202 views

PostgreSQL Schema Builder/Diagrams [closed]

I have worked with PostgreSQL, primarily using the Django ORM (started with MySQL and migrated to PostgreSQL) and using pgAdmin for maintenance tasks. I am now working on an open source project ...
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1 answer
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Can I show a relation - "Either in this table or in that " in ER diagram?

I am making a database for handling leave applications in an academic institute. Given that there is hierarchy existent in such institutes, and I need to keep record of the people that were at these ...
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1 vote
1 answer
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Entity Relationship Diagram - Entity depending on attribute

I have an ER-Diagram containing the entity employees. When employees have high skills they may supervise lower skilled employees. How can I model that in an ER-Diagram? My initial approach of was to ...
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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 ...
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2 votes
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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, Address ...
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3 votes
1 answer
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Setting up relationships on a gaming schema with multiple locales

I've devised the following schema: Where BotLocale holds locales like en-US, es-AR, etc. GameArtifact has a primary key which is artifact_id and GameClass with locale, identifier being the primary ...
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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/...
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2 votes
2 answers
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How to Represent Equation with Variables in Relational Database

I am building an application to store the different formulas used for different subjects in school, and I have drawn the following database diagram to depict that scenario: I am having trouble ...
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Replacing the removed database diagrams feature [closed]

I have a SQL Server database and want to create an ER diagram for it, to analyze tables and relationships. The option to create a diagram is no longer present in SSMS 18. Is there any free tool ...
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8 votes
2 answers
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What do the entity-relationship diagram (ERD) symbols used in DBeaver mean?

I don't understand the ERDs used by DBeaver. The diamonds and dots at the ends of the line arent the crow's foot I'm used to. I've googled the subject and checked the docs but can't find a straight-...
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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 ...
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1 vote
2 answers
519 views

Error 1005 when Forward Engineering EER diagram

I have created an EER diagram (as shown in the image bellow) in MySQL Workbench and wanted to Forward Engineer to build the DB. After configuring the model options to the Target MySQL Version and ...
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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 ...
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1 answer
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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 ...
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1 answer
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Modelling products along with their attributes and discounts for an e-Commerce database

Scenario My application will have products belonging to 1 company. Each of those products will: Have at least 1 quantity Have 0 or more discounts Have 1 or more attributes Belong to 1 category, which ...
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1 vote
1 answer
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SQL Server Database Diagram

I am using SSMS v18, I need to create an ER diagram from my database. As Microsoft removed diagram from new version of SSMS (v18) so now How can I get a diagram for my database??
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1 answer
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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 ...
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2 votes
2 answers
867 views

Does the relationship between teams and matches have a many-to-many cardinality ratio?

Diagram I created the following diagram: Considerations So I will create two tables, one called Match and the other one called Teams. In Match there will be data about two teams, Away and Home. Let ...
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