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Questions tagged [database-diagrams]

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12
votes
3answers
5k views

Modeling a scenario in which each Music Artist is either a Group or a Solo Performer

I have to design an entity-relationship diagram (ERD) for a business context that involves the delineation of music artists, as I will detail below. Scenario description An Artist has a Name, and ...
9
votes
2answers
8k views

What is the best way to create a database diagram for SQL Azure without having to install SQL Server?

I have a database on SQL Azure and want to create a database diagram for that, but don't want to have to install SQL server and copy the database etc. Is there any way that I can do it that anyone ...
8
votes
1answer
19k views

Ternary relationship: what's the difference between having single table and having multiple tables?

Consider the following ternary relationship: Suppose that all entities have only two attributes (PK and Name). Here are the tables I derived (5 tables): Sector ------------------------- ID_Sector ...
7
votes
4answers
2k views

Is it critical for a database to have a relationship table/diagram or not?

Got a question and wanted to get the best practices or thoughts on this. I have an application that was developed with a SQL Server back end (site is Entity framework, vb.net, asp.net). The original ...
7
votes
1answer
1k 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 ...
7
votes
4answers
111k views

How to represent foreign key in an ER diagram?

Suppose I have a 'Transactions' table which has a column 'Customer ID' (Foreign Key) and a Customer Table having 'ID' (Primary key). How do I show the relation between the two tables and showing that ...
6
votes
1answer
996 views

Postgres 9.6 export the database structure as pdf [closed]

Is there any tool/software the can export all the tables structure (column names , its datatype ) in the database as a pdf/excel/word. additional diagram export will be added advantage.
5
votes
3answers
6k views

How do I read ERD Notation (crow's feet) to convert to Natural Language?

Background I am attempting to insure I understand how to read ERD (Entity Relationship Diagram) notation so I can convert it to a natural language explanation. I'm trying to insure I can explain a ...
5
votes
2answers
311 views

How can I represent the entity types depicted in an ERD as relations with attribute names?

I have created the entity-relationship diagram (ERD) shown below (for brevity, each individual bubble-shaped box portrays multiple attributes): Considering such an ERD, I have to convert each entity ...
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 ...
4
votes
2answers
4k views

Is my ER Diagram correct? Why use relationships?

This is the first time I've made an Entity Relationship Diagram (ERD) for database that will be built on MySQL. The business domain of relevance is about equipment issues management. Prior to this, I ...
4
votes
2answers
5k views

How to generate the E-R Diagram of Wordpress using mySQL Workbench

I am trying to generate the E-R Diagram of Wordpress using the 'Reverse Engineer' feature. There is a slight obstacle though. The diagram does not show the relationships between the entities. Is this ...
4
votes
1answer
665 views

Modeling Subclass (or Subtype) Constraints in an Entity-Relationship Diagram

Scenario description Can someone help me out on how to model the situation that follows: There is a superclass (or supertype) called PRODUCTS, which has the subclasses (or subtypes) named FOOD and ...
4
votes
1answer
455 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, ...
4
votes
1answer
7k views

Database design for an exam system

I am working on creating a simple exam system, in which you are going to be basically able to store students, classes, exams, questions and scores(and some other stuff that those depend on). I am also ...
4
votes
2answers
230 views

Can relationships have relationships?

I have the following requirements (as part of a larger system). In the database, I need to maintain a list of parts, suppliers who sell those parts. Many suppliers can sell the same part and each ...
4
votes
1answer
922 views

How to model an “is a” relationship in an ERD using Crow’s foot notation?

I have to create an entity-relationship diagram (ERD) for an assignment. I am doing this in a particular drawing tool with the Crow’s Foot notation. There is however one thing I cannot figure out: ...
3
votes
5answers
14k views

Automatically create ER diagram from database schema

I have a database with 193 tables and I need to create an entity-relationship diagram from them. There are no formal relationships between the tables with respect to FKs. The relationships are mapped ...
3
votes
2answers
8k views

Financial database design

I am working on an application to store financial data and need to model the tables where the data for several financial statements will be stored. I came up with the following two designs but I can't ...
3
votes
3answers
4k views

How can I get a list of tables contained in a database diagram?

I need to get a list of the tables contained in a diagram in SQL Server. How can I do it using an SQL script? I don't need a list of tables in the database, but the list of tables contained in a ...
3
votes
3answers
2k 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 ...
3
votes
1answer
873 views

SQL Server 2008 Script Changes from Database Diagram

I have a database diagram which I have made several changes to using SSMS, however instead of committing the changes I want to generate a SQL script to apply them instead. Is there a simple way to do ...
3
votes
1answer
34 views

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 ...
3
votes
1answer
800 views

Ternary Relationship or (n-ary)

I'm trying to find the difference in terms of modeling a ternary relationship v/s a binary relationship in the following case. Any piece of advise would help me a lot. Company has editors who are ...
3
votes
1answer
938 views

Is my shopping list database schema good enough? [closed]

I'm wondering if my schema is correct? It's intended to hold shopping list items for each user, a user belongs to a household. Items will be added to the household. The stocklist will to hold the ...
3
votes
1answer
14k views

Number of ISA relationship triangles in an Entity-Relationship Diagram

The following two diagrams are nearly identical. However, in one, there are two ISA triangles from the Entity "Movie" and in the other there is just one. What is the difference in meaning?
3
votes
1answer
1k views

Learning to draw entity-relationship diagram for a scenario involving Offices, Employees and Projects

I am trying to learn entity-relationship diagram, following question is the objective. Information consulting firm has number of offices with employees. The employees can move offices depend on the ...
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
780 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
1answer
207 views

Scripting Creation Of Database Diagrams

Is it possible to script the creation of a database diagram using T-SQL? If not, what is the Database Diagram Designer doing when you use it to save / edit a diagram (is it using PowerShell or some ...
2
votes
2answers
894 views

What are the bad design points in the following (simple) Entity-Relationship Diagram?

The objective is to design an Entity-Relationship Diagram for a company that has addresses, telephones, emails and representants. Here's the list of the constraints: a company has one or more ...
2
votes
1answer
6k views

Representing a Superclass/Subclass (or Supertype-Subtype) relationship in a MySQL Workbench diagram

Situation I am trying to figure out how to represent a one-to-one (1:1) relationship regarding a superclass/subclass or supertype-subtype structure in an entity-relationship diagram (ERD) of the kind ...
2
votes
1answer
203 views

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-...
2
votes
3answers
2k views

How to interpret ternary relationship

I have tried to search online on how to interpret these ternary relationships but haven't found any clear answer. Since I don't understand how to interpret it I am having trouble changing it into ...
2
votes
1answer
79 views

Understanding Table design in database [closed]

I have 3 years of SQL Server development work experience. Now I am moving to a new company (first jump). I heard in my new company they deal with too many tables. What is the best way to understand ...
2
votes
2answers
7k views

What does the Union sign in EER diagrams mean?

I know disjoint and overlapping, but what does the union like sign mean in an enhanced entity-relationship (EER) diagram...? For example: In other words, what does this diagram mean?
2
votes
1answer
135 views

Database templates [duplicate]

Are there any site with database templates for specific purposes? (i.e. a database schema for users and authentication in a webpage) for different databases like Oracle, MySQL... I have been looking ...
2
votes
1answer
11k views

MySQL Workbench EER Diagram and ENUM data type

I am creating EER model diagram using MySQL Workbench (version : 5.2.47) The version for MySQL, I am using is 5.5.35-0ubuntu0.13.10.2. I have created a schema with 'Default Collation' set to 'utf8 - ...
2
votes
1answer
3k views

ER relation with unique key

I've a problem about my ER diagram. Assume that I want to draw a diagram with student, member and team. Here is my specs: A student does not have to be a member of any team. A student could be a ...
2
votes
1answer
674 views

Conversion of simple ERD to Table: is the solution below any good?

Consider the following ERD: Suppose that all entities only have two attributes: a PK plus a name/number. I want to convert that ERD to tables. Is it needed 4 tables (1 for each relationship plus ...
2
votes
1answer
3k views

Database Normalization: A Case Of The NULLs [duplicate]

I'm trying to learn about proper database management and am having a hard time with designing a database that doesn't rely on NULLs. If you think I'm crazy for embarking on this, it is because of SQL ...
2
votes
2answers
87 views

Two paths between two entities

In my db the entities are: designed_object: a generic designed object designed_object_param: a parameter related to the designed object with the type (param_type), the default value (param_value), ...
2
votes
1answer
52 views

Can someone please tell me where I went wrong for an exercise submission?

I recently submitted an assignment in a group for our databases class and we lost points on one of the exercises and the correction is unclear. If someone could examine the question, the submission ...
2
votes
1answer
760 views

I created a DB schema for a project relating to collecting comments for web pages, is relational the way to go and how are my relationships?

I'm curious if relational DB is the way to go, if the current relationships in the diagram make sense, and whether it will bode well for coding.
2
votes
1answer
156 views

Database Design Techniques, Notations and Terminology

I'm taking a Database course and I'm a bit confused with the different types of graphical representations terminology of a database design. Are Data Model, Crows Foot Notation, Crows Foot Model, ERD &...
2
votes
0answers
32 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
2answers
53 views

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 ...
2
votes
2answers
86 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. ...
2
votes
0answers
167 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
1answer
692 views

Do you know if this are examples of non-identifying or identifying relationships?

Im using MySQLWorkbench to model a diagram. But Im with some doubts about identifying and non-identifying relationships. It seems that all relationships of the project are identifying. For example, a ...