For questions regarding the use of the relational model for databases.
Questions tagged [relational-model]
56 questions
0
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0 answers
Relational model for java composite pattern
I have classes that follow a composite pattern relationship for which I need to create the relational data model for Oracle database.
The (java) classes are as below -
class AbstractEmployee {
int employeeId;
}
class Employee extends…
Sudhanshu Mittal
- 143
- 4
0
votes
2 answers
How to design table with primary key and multivalued attribute?
I'm interested in database design and now reading the corresponding literature.
Through the book, i have faced a strange example that makes me feel uncertain.
There is a relation
In this table we have a composite primary key (StudentID, Activity).…
metacube
- 328
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- 14
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1 answer
Mapping ER Model to Relational Model
I was going through this site to understand ER to relational model mapping.
Below is the link:
ER Model to Relational model
Consider case 1: It says that since the passport entity type is in total participation, we can merge person and passport…
Aditya Naidu
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1 answer
What's the difference between relational diagrams, ER diagrams and EER diagrams
I got confused when someone spoke of relational models when I asked a question about EER models. I've learned about the difference between ER and EER diagrams, but I'd like to understand the whole modelling process... I know EER are enhanced ER…
user1534664
- 3,258
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1 answer
Laravel relational delete between three models
I have a simple relational models that I've built like that :
Parent :
hasOne('Gallery', 'object_id')->where('type', '=',…
Thoma Biguères
- 1,136
- 4
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- 42
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votes
1 answer
Backbone localStorage and relations
I'm having two RelationalModels, Student and School. School has many Students. All the data is to be stored in Backbone.localStorage
I need advice how the following should be done:
I suppose I need two collections, one for each model, Student and…
user1121487
- 2,662
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1 answer
Composite key with user-supplied string column, foreign keys
Let's say I have the following table
TABLE subgroups (
group_id t_group_id NOT NULL REFERENCES groups(group_id),
subgroup_name t_subgroup_name NOT NULL,
more attributes ...
)
subgroup_name is UNIQUE to a group(group_id).
A…
akp
- 21
- 1
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2 answers
Solving ternary to create the database
I have this tables:
movie, session (a movie displayed at a datetime) and User.
Users can make reservations for a movie at a concrete session. Drawing it i have it like:
movie **1** ----- **n** sesion
|
**n**
…
Alvaro
- 40,778
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- 164
- 336
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1 answer
Unique kind of questionnaire - Database design
For a research experiment I need to design a web application that implements a particular kind of questionnaire, the results of which will serve to derive some statistics and draw some conclusions.
In short, the questionnaire has to work as…
Desperados
- 434
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- 13
-1
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1 answer
What are the likely FDs(Functional Dependencies) for this relation?
ABC(doc-firstname, doc-surname, doc-gender, doc-rego, doc-qualification, pat-ID,
pat-givename, pat-surname, pat-gender, pat-DOB, pat-addr, pat-phone, app-ID,
app-datetime, app-type)
● A doctor has a unique registration number (doc-rego) and is also…
user24529
- 155
- 1
- 2
- 5
-1
votes
1 answer
data modelling of land vs owner vs type of ownership.? Please comment
I have just stared to learn data modelling and would like your views about the way that I have designed my logical model and physical model.
The problem.
1) A person can own multiple land parcels.
2) A land parcel can be owned by multiple…
frank
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