I hypothetically have a publicação table that has, by default, the autores attributes (derived from a relationship table), titulo , edição , editora and ano . However, depending on the type of publication (...
How to model the Product table of a database? This table should store the following information: id, product name, quantity, price, status (if it is in stock, if it will be returned) and information pertinent to each type of product: food (nat...
I think this question is more about modeling analysis actually do not know if it fits into the standard questions discussed by meta.pt.stackoverflow.com . I need to make my system in a way that almost everything will have user permissions, I ma...
I was arguing with a friend of mine about using views (say MySQL, not the pattern MVC).
A question arose in the following way: A Model serves to represent a data structure, being able to read and write data in a table through it.
So, co...
In the application I'm working the database is built on the users part, as follows:
user 1 -------> 1 user_address 1 <-------- 1 address
In the user table there is no column that references the address. What exists...
According to the definition of this site :
CARDINALITY
It is the maximum and minimum number of occurrences of an entity that are
associated with the occurrences of another entity that participates in the
relationship. That is...
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...
I have a scenario where I have the entities Pedido and Usuário . The Pedido is composed of some attributes, among them the requestor that is mapped as follows:
@ManyToOne(fetch = FetchType.EAGER)
@JoinColumn(name = "usuario...
I'm looking for information on the cascade types that exist and how they work in relational modeling with JPA. The types I found explanations were:
NONE = Do not do anything with the object (default)
MERGE = Update children when updat...
I have a database with three entities that relate: user, process_selective and courses. The goal is to model the bank to meet the following requirements:
User can subscribe to multiple selective processes
Each selection process may or may...