Questions tagged as 'entidade-relacionamento'

Tagged questions
3
answers

MER - Cardinality temporal confusion

I have some temporal doubts. Example: [FUNCIONÁRIO]------<PERTENCE>------[DEPARTAMENTO] In this case it is obvious: each employee belongs to one department, and each department has N employees (either currently or over time)....
asked by 28.08.2015 / 10:41
2
answers

Conceptual Model

I was looking at the conceptual model diagrams, I saw some that contains the Attributes and Entities like this: AndothersthatonlyhavetheEntity: Which model is correct? or are the two of you? Is it necessary to identify attributes in...
asked by 30.04.2016 / 02:42
3
answers

What is the relationship between DER and relational database?

What is the relationship between DER and relational database?     
asked by 19.10.2016 / 00:08
1
answer

Two classes mapping the same table with the Entity Framework

I'm trying to make entity map two classes to the same table this is possible? Scenario: My identity is decoupled (Eduardo Pires' tuto) from my domain and from the presentation layer on the domain layer I have a usuario...
asked by 17.01.2017 / 00:13
3
answers

Many to Many JSON POST - Rails 5 - Only API

Hello, I'm developing an Engine in Rails 5 where it will be just a blog API. It will be a simple system. Post has several Passions and Passions has several Posts. I made the N < - > The problem is that when sending the JSON of the post...
asked by 29.03.2017 / 13:28
3
answers

How to find relationship and cardinality in MySQL?

The image below shows a relationship between two tables created from the MySQL Workbench. What I need to know is how I can find this information inside the database. I need to know exactly what type of cardinality (1: 1 or 1: n). I've a...
asked by 29.09.2015 / 00:21
1
answer

Entities classes

I'm developing a sales project to which I have registered a funcionário that can also be vendedor , I will have a cliente that can be a pessoa física or pessoa jurídica , fornecedores that can be pessoa...
asked by 11.07.2018 / 13:40
2
answers

How to normalize this small database?

I'm trying to improve this small database of the TCC's technician, he's very small, it's from a small page to a trade, in which I would have a catalog of products and deals to attract buyers to the physical store. I hope you can give me some tip...
asked by 26.02.2018 / 02:10
2
answers

What is the difference between Associative Entity and Intermediate Table of Relationships N for N?

What is the difference between the Associative Entity and the Intermediate Relationship Table N for N ? Is there any noticeable difference in the translation of the ER template for the relational model ? In the ER model associative enti...
asked by 07.01.2017 / 19:51
1
answer

How to limit a 1 relationship to many JPA?

I'm using JPA with Spring Framework in a project, I'd like to limit a 1:n relationship, I want to 1:5 , how do I do this? > The relationship is this: @ManyToOne private Task task;     
asked by 26.10.2016 / 13:17