Questions tagged as 'modelo-relacional'

Tagged questions
2
answers

How To Reference Foreign Key Alternating Tables

I have a Database of City, State and Country. But I want to add Cities to my table and it does not always contain a State to be referenced. However, every city is located in one country. My question is: can I create a relationship in which...
asked by 05.08.2015 / 21:07
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How do I insert into a ternary relationship?

I am creating this template yet I do not know if it is correct. Because I have basic knowledge in database. How do I insert into a ternary relationship that happens in Supplier - Suppliers_has_product - Product?     
asked by 22.03.2014 / 14:42
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answers

Ruby on Rails Modeling

I have a question that I can not see how to resolve. I have to run a stock program in Ruby on Rails that contains some hardware, which will contain some insights. For example, I will have computers, printers, phones, among others, each wit...
asked by 04.10.2018 / 17:55
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Mapping of list with sub list of tables for class

Hello; I have always had a question in this mapping, but in the current project I need to resolve it. It's the following, I have a Message table and a user table. I need to relate the users to the messages seen, to detect if it is a new messa...
asked by 19.08.2018 / 17:04
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Database, logical and conceptual model

They can help me in these logical and conceptual models, I wanted to know if this right or wrong the one I did to deliver, is from a car rental company.     
asked by 16.04.2018 / 00:43
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Connections in MYSQL Workbench

Good evening, could anyone give an explanation of the difference of a dotted and continuous relationship in MYSQL Workbench? Is the following activity correct? Ready activity: Activitystatement:     
asked by 18.06.2018 / 04:24
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Problem with the relationship in the Motherboard (Inheritance) in PostgreSql

I have the Mother Table Payment: CREATE TABLE pagamento ( pagcod serial not null, CONSTRAINT pk_pag PRIMARY KEY (pagcod) ) And the two daughters tables Money and Credit Card: CREATE TABLE dinheiro ( desconto numeric(10,2) DEFA...
asked by 02.11.2017 / 06:32
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Persistence with inheritance, one-to-one relationship and manual primary key

I am developing a web heritage project to finish my degree. I'm using Java (IDE: Spring Tool Suite), Spring, Hibernate and Mysql. I'm having a data modeling problem that I can not solve: An Equipment class must have an asset number a...
asked by 07.10.2017 / 22:47
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1: 1 relationship with abstract class in EF

Okay, everyone? I have the following problem: I have two Person and Property classes that may have an address, but the < strong> Person can have 0: N Address and Property 0: 1 . Knowing this I've transformed the Address class into...
asked by 12.10.2017 / 20:41
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answer

Relationship 1 - 1

I'm having a bit of trouble drawing my relational database model. The idea follows the following principle: You would have a login system, and for this a table user There would also be 3 types of people who would log in to the prod...
asked by 16.09.2017 / 01:32