All Questions
216
questions
-3
votes
1
answer
137
views
Using one shared Join table for multiple many-to-many relationships [duplicate]
I have these SQL models: Albums, Collections and Photos.
Both Albums and Collections have a many-to-many and one-to-many relationships with Photos and serve different application purposes.
What are ...
- 775
-1
votes
1
answer
249
views
What's the relationship between metadata and data model?
Is is appropriate to consider metadata as the instance of data model?
I am sure that in relational DBMS, foreign key is part of its data model, and the specification of foreign key is kind of metadata....
- 360
0
votes
1
answer
191
views
design database for dictionary application
I'm trying to make a dictionary application but having a hard time designing my sql database (I'm very new to databases).
Here's the problem:
I want to store entries, entires can be words or sentences....
- 248
0
votes
1
answer
249
views
What's the relationship between Logical Model and Data Model?
I have read this post and still confused.
Both Logical Model and Data Model seem to be used interchangeably to some extent, considering they are both distinct from Conceptual Model/Semantic Model (...
- 360
0
votes
0
answers
1k
views
What's the difference between a DataMart and a Fact Table?
I actually don't understand the exact meaning of DataMart.
For instance , if my datawarehouse has 4 fact tables , does that necessarily mean I have 4 datamarts?
These are the HR fact tables I have.
...
- 279
1
vote
1
answer
322
views
Null Foreign Keys in Fact Table
The data source I'm using for the fact table may include missing Data (NULL). For example for an employee, some "Department names" are missing and I already have "Dim_Department" ...
- 279
-1
votes
1
answer
261
views
Can I store textual fields in fact table of Datawarehouse?
I have a fact table called Fact_Employee_Ratings, these are reviews about a company scrapped from Glassdoor. The review is actually divided into two parts, employees would give what they liked and ...
- 279
0
votes
1
answer
52
views
UML ERD Database modelling Query [closed]
I have the following tables in my database.
(Member) is assigned to 1.m facility
(Facility) has assigned 1.m member
(Facility) enrolled to 1.m program
(Program) enrolls 1.m facility
I want to query ...
- 3,174
0
votes
0
answers
449
views
Login Entity Relation Diagram: Review and Opinions
I've made a try of an ERD, to model a login system to manage employees, accounts, netkeys, usernames and passwords in an enterprise, but I still think something's missing or could be improved.
So for ...
- 1
0
votes
0
answers
25
views
Conceptual Model linking multiple tables by Year
This is maybe a very basic question, but I'm trying to model something, ideally with a start schema. I've provided some dummy data.
The first table just lists out "Scores" (not too important ...
user14380579
1
vote
0
answers
199
views
Can I have a one-many relationship between a super-type and each sub-type?
I am trying to model a scenario where I have a SuperType that has 2 Sub-types. However, each Sub-Type has several records associated with an instance of the Super-Type.
Let's say there is a Book and ...
- 973
0
votes
1
answer
606
views
How do you answer a question when asked what is the granularity of the data you worked on?
I have been asked the above question but i know only its meaning that its the finest level of data. for example, if you have name in fact table, then its detail such email, phone number,etc can be ...
- 155
0
votes
0
answers
673
views
What is the best practice in terms of Bank Acount Primary Key. AccountNo or AccountID?
In many Bank Account applications' implementation, Account Number is always set as Primary Key. I was thinking what if the customer who is the account holder decides to move to a different Bank and he ...
0
votes
1
answer
601
views
Deeply nested one to many relationships in database design
I am designing a database model that is based on a risk analysis table which is similar to the following (apologies for the example quality):
Basically, the user should be able to create such tables ...
1
vote
1
answer
624
views
Modelling ER diagrams with weak entities
If an entity, say x, is dependent on multiple other entities but x does not have any key attributes (so x can not be a weak entity?). Then how should x be modelled in an ER diagram, assuming x has ...
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