Most voted "relational-model" questions
Relational model is based on two concepts: Entity and Relationship. Entity that is the one that contains the data and relation that is the way these data are associated.
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answers490
viewsPhysical and Juridical Person
I have a field which can receive physical or juridical person, as you model it ? through interface, composition or heritage ? I have the following class structure: Contacts (PF only) -- belongs to a…
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answers19
viewsWhat is the relationship between EER and objects?
The EER (Enhanced Entity-Relationship) model has some concepts such as class, subclass, generalization, specialization. What is the relationship between these EER concepts and object orientation?…
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answer280
viewsDoubt database / batch control system
I’m working on a project where I came across a problem where I don’t know what would be the most efficient way to do it. My project has a register of products in which I want to control by lot,…
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answers597
viewsMany to many ratio between various tables
I know that between two tables in a ratio of many to many 'we need' (not mandatory, but facilitates) a third table pivot which is what conventionally relates the ids of one with the ids of the…
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answer228
viewsPHP/Mysql - Print values with relation between tables
In a system I need to print paint cans and each one has its own colors. I did it in a way that works, but repeats several times the requests in the database. I made two tables(Example): latas…
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answer983
viewsRelationship 1 - 1
I’m having a little trouble designing my relational database model. The idea follows the following principle:: It would have a login system, and for that a table user There would also be 3 types of…
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answer860
viewsJoin between tables that do not relate directly
I have three tables: Candidate who has an ID as pk (which has been invented) Registration that has FK for Candidate ENEM that has no id representing the candidate, only his registration and…
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answers154
viewsInheritance persistence, one-to-one relationship and manual primary key
I’m developing a heritage web project to finish my degree. I am using Java (IDE: Spring Tool Suite), Spring, Hibernate and Mysql. I’m having a data modeling problem that I’m having trouble solving:…
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answers118
viewsRelationship 1:1 with abstract class in EF
All right, guys? I have the following problem: I have two classes Person and Property who may have an address (Address), but the class Person may have 0:N Address and the Property 0:1. Knowing that…
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answers275
viewsRelationship problem in the Mother Table (Inheritance) in Postgresql
I got the Mother Pay Table: CREATE TABLE pagamento ( pagcod serial not null, CONSTRAINT pk_pag PRIMARY KEY (pagcod) ) And the two daughter tables Cash and Credit Card: CREATE TABLE dinheiro (…
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answer68
viewsIs it possible to say that the scheme is normalized in 3FN?
Explaining the Context In the internet found an example of a scheme described in this way: account(num-conta, descr-conta, launching(num-lanc, tipolanc, data-lanc, valor-lanc)). Notice that the way…
database modeling relational-model relationship normalizationasked 7 years, 2 months ago Jonathas B. C. 883 -
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answers104
viewsModelling Ruby on Rails
Guys I have a question I can’t see what the way to solve. I have to perform a stock program in Ruby on Rails that contain some equipment, which will contain some avergiguações. For example, I will…
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viewsInserting Id of a Foreign Key into a Relational Database
Good morning. I am beginner in Database and programming and have a question, which query to recover the id to insert in a table with foreign key? I am using the MYSQL database. Example, I have the…
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answer70
viewsRelational Model of a Bank
The question is this, I have the following situation: On the right side I have the mathematical knowledge - MK and on the other side Conhec. Didactic - PCK, let’s call them Domain, and in each of…
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answers131
viewsHow to relate questions to a question
This question is not directly linked to code, but and the basic part of my project, I am currently divided into 2 options (which I will describe in detail below). Currently the UML is this way,…
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answer316
viewsMinimum and maximum cardinality - Relational Model
Guys, I’m very much in doubt of these 2 tables... Right, I asked 2 questions for my tables: User, you can register how many courses? A: None or N courses Course, for you to be registered, you need…
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answer92
viewsTernary Laravel Relationship
I’m creating a polling system where I have the following tables. A poll has several options. An option belongs only to a poll. A user can vote in multiple polls, but one option per poll. Soon I made…
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viewsDoubt for database structuring - SQL Server
Good night! I would like to ask for help to have some ideas, I will explain more or less what I would like: Let’s say I have two databases, one to serve as Central (receives information from various…
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viewsProblems with Table Modeling with Two Foreign Keys
I need to finish a modeling of a database and I’m at an impasse. Simply put, I have 3 tables as follows: PROMISSORY NOTES CREATE TABLE IF NOT EXISTS `picinin`.`promissorias` ( `id_promissoria` INT…
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answer54
viewsHow should I structure my database?
I am studying Mysql and have a user system. When the user logs into the account it is possible to create annotations. I imagine the right user table, but what about the notes? Should I create a…
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answers523
viewsA phone chart for each customer or just one for all customers?
Currently in college we learn like this: It has a client entity, this client has its attributes and one of them is the phone, I want it to be possible to register several phones, we create a single…
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answer27
viewsProblems with the database
Well guys I created an account in aws, to manage it with mysql I wrote the password the user and I’m sure that this disgrace does not log, already Mechi in ec2, I put to be accessed by any ip with…
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answer98
viewsDoubt - Relationship N to N
I’m developing a conceptual model for project management. A Project can have several phases. One Phase can be in several projects. The above relations will generate another table "Projectophase" .…
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answer766
viewsRelational library model, huh?
This model I made this cool or is redundant yet? [Edited] The database has been modified. Can I now have better queries? Here’s how it is now:…
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answer360
viewsSequelize error when performing BD registration [Model.hasMany called with Something that’s not a subclass of Sequelize.Model]
I’m doing a Ode project, using sequelize as ORM. I have 4 tables relating [Factor, Subfactor, Obs_factor, Goals], when I will run the create of this error: Error: Factor.hasMany called with…
javascript node.js postgresql relational-model sequelize-jsasked 4 years, 11 months ago Tarcisio pieroni 3