Questions tagged [data-modeling]
Elaborating passive data structures based on the analysis of data requirements for the purpose of designing and implementing standardised data formats, databases and data processing systems.
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Data Flow in Data Flow Diagram
Consider the following level - 0 dataflow diagram for a patient management system :
Consider the doctor entity, the system provides an appointment report to the doctor. If the system only generates ...
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Modeling a CSV file: What is the standard? Python or SQL?
I have a wide CSV file of about 350mb, and want to load it into a SQL database and properly model the data to make it easier to use for analysis.
I could split the data into tables with python and ...
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3 QAbstractListModels versus 1 QAbstractItemModel
This is a simplified representation of the existing data structure I have in my code (The actual data structure is composed of classes), the data of which I need to display and modify via multiple ...
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using same table for multiple features a bad coupling?
We are migrating a template that was a mere questions array questions
[
{
type:text,
name:first,
value:What is our name
},{
type:radio,
name:favourite fruits,
value:[
...
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5
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Data Modeling: Are technical concepts within a tool that implement a business entity entities as well?
I believe this forum is the correct one for my question, based on the community guidelines but let me know if not. It seemed like the best fit.
I am performing a data modeling exercise to formulate a ...
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An IoT client and MVC-based server. Data model with different fields per type?
The problem
Let's assume such scenario:
List of IoT devices (one model?)
Each list item has (among other fields) a type field
Depending on the value in the type field, device may report different ...
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Tradeoff: Fetching less data vs having a simpler data model
We have 2 vehicle types in our system Car and Bike. Both can be associated with a Report.
There are components in our system which operate on Report but when dealing with the report they need to check ...
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Should I duplicate or inherit a python dataclass which changes attributes based on the version of an API endpoint?
I'm working on a python library for a REST API.I'm using python data classes to represent the structure of the returned JSON
The v2 of this API returns a slightly different object when compared to v1.
...
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Python - Where do I store data classes which are common across different files?
I'm working on a python wrapper for a REST API. I'm using python data classes to store the shape of the JSON response of each endpoint so developers have features like autocomplete and objects they ...
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User (Actor) data shared across Domains / Microservices
I have read through a number of posts on Software Engineering but am unable to find a suitable solution for the problem my team and I are trying to solve.
We are building a system where we have ...
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How to model a ternary relationship in a graph-based paradigm?
Consider a context where we have Users saving Questions and adding personal Tags to them.
In a graph-based paradigm, a first approach could be something like:
(User)-[SAVES {tags}]->(Question)
...
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How to document a NoSQL document-based data model?
How do you document the logical data model of a document-oriented database like MongoDB?
For relational databases, Entity-Relationship diagrams or UML class diagrams are used.
What is the practice for ...
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Is there a difference between these two data models?
Let us say I want to store on a database a userID, their nationality and if they are from the UK their UK passport number.
I could model this by having one table with userID as primary key, ...
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Thinking about data as object vs table row [closed]
It often happens that we have a set of structured data. Let's say our data is about charitable organizations. I could turn it into a list/set of objects/structs:
struct Charity {
let name: String
...
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1
answer
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How to draw an aggregation relationship in the Crow's Foot Notation?
I was stuck on a relation description and unable to model it in the Crow's Foot Notation:
Each individual vehicle is a particular model of a particular brand offered by the company (e.g., the XF is a ...
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What to do when putting logic into the database seems to be the only option?
I am currently working on an application that models a complex business process that consists of many steps, each having a 1:n relationship with subsequent steps. The software is written Java using ...
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How to change a data model
In my model a user entity has three attributes : ID, name, hasBoyfriend.
I want now to change hasBoyfriend to boyFriendsNames which is an array of names .
The user entity is used by many services.
The ...
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Can we do domain modelling or create domain entities/models in NoSQL like Amazon DynamoDB? If yes then how?
Recently I was going through an article (link at the end) on AWS for DynamoDB NoSQL and got to know that they are suggesting to only have a single table with certain access patterns in your NoSQL ...
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Rebuilding a legacy application : What about the data model?
I am currently rebuilding from scratch a product catalogue (to feed a shopping website).
The existing legacy system is heterogenous, Long story short : The some products are stored in a FileMaker ...
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Attributes at the fact table in dimensional data model
I know that a fact table in dimensional data model consists of measures and flags for an event or transaction. I also understand that it may contain date of the event. I have to design on fact table ...
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What is the normal form of JSON?
This is going to sound like a trivial question, but I like to think it's actually a deep one. The simple quesiton is, "What is the normal form of a typical JSON object?" For reference, I ...
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IoT Data Model Standards
I am currently trying to model IoT devices within buildings. I could start from scratch and develop the data model myself, but this seems like a common problem which will have been solved multiple ...
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Introducing "status" column to an SQL table changes its definition
I saw this pattern in multiple projects I wrote: I create an SQL model for a certain type of entities and at some point, we realize that there's a need to store multiples types of the same entities. ...
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What kind of Relations should I have in my E/R Diagram
I am trying to create an Entity/Relationship Chen Diagram for a new APP. Scope is simple enough.
I will have multiples types of users login through the same Login Form.
What I decided to do... Is ...
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Applying Domain Driven Design to an analysis driven domain
I am currently working on a domain that is fundamentally driven by analytics. I'll use a fictitious example to illustrate my question.
Suppose the application is a service based on House Prices. The ...
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SQL Database schema for Catering/Menu management
Background
I'm building a Private Chef booking service where you can book a Chef to cook you a custom Menu. I'm having trouble creating a SQL db schema that accurately represents the domain while ...
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Database Model Classes in TypeScript
I'm using Knex.js with TypeScript for database access.
Table
uid (UUID, auto-generated by Postgres)
name (varchar)
Model
interface User {
uid: string | null;
name: string;
}...
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1
answer
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Data Flow Diagram for patient information system for a hospital
I have an example for a DFD for a patient information system implemented in a certain hospital. The below figure, represents the overview diagram (level 0-diagram, if we consider that the first level ...
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How to represent a data model?
Often enough, the terms data model and data format are used interchangeably, but here I disagree. Let's start with the simpler one, the data format. I don't know exact definitions, but the data format ...
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How to avoid code duplication from handling "structually similar types" in Scala?
Often, when programming, you'll have different degrees of information to you in different contexts.
For example, a web server may have two routes, which recieve information about a Person, one of ...
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Is Excel data model as good as or better than Microsoft Access?
I'm working with several Excel worksheets and workbooks that need to consolidated or linked to each other. These workbooks will track client interactions for different team members.
I did the initial ...
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API Request/Response Model for showing differences in JSON objects
I am writing an API to merge two different JSON Objects.
Both of these objects can have same as well different number of properties.
Object 1 :
{
"name": "Sam",
"lastName": "Hanks",
"...
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Optional relationship on ERD diagram
Upon generating an entity-relationship diagram of my database I observed several occurrence like this:
This diagram (in IDEF1X notation) shows the following:
Our team's DB convention is that each ...
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Correct place to store semi dynamic data
What I mean by semi dynamic data are data that are expected to be changed only with product versions.
Now imagine this scenario, In version 1 of the product, I have item status : SUCCESS , FAIL
In ...
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When self-referencing in a table, do you prefer `parent_id = null` or `parent_id = id` for a row referencing to itself?
For the discussion, I will provide my example. But I am interested in the broad guidelines.
I save in my postgres DB legislation (law texts) composed of a single header (H), paragraphs (P), sub-...
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Many-to-many assignments in user system
I have a few software architecture/design questions related to a technically quite simple problem. We already have all the functionality implemented properly, however from a design perspective it is ...
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Best way to model assay steps with low variability?
I have to process biological data input in the format of 96-well plates.
explainer for the non-biologists:
These plates are basically a 2D matrix of 8 rows x 12 columns of small cups called wells. ...
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Help designing a product model with vast amount of properties
I've been asked how to re-design a legacy system by a relative for a company that builds custom chairs. On their website you can customize your chair in about 30 permutations : chair type, material, ...
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Creating a "pass-through" dynamic model
We have a layer that exists in our architecture that, for lack of a better term, bears the responsibility of defining the common models. In other words, when systems need to communicate, rather than ...
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What kind of diagram best represents the field-level mapping from one system component to another?
In my environment, we have multiple systems developed independently by different teams. Those teams frequently recreate the wheel because they're building applications, not building blocks.
As a ...
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ER diagram - feasibility of a requirement
I need to model the following requirement in an Entity-Relationship diagram.
"Customers place orders, which contain a list of products with their quantity and prices. A shipment is made when ...
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How to create a flexible datamodel?
I'm trying to create a flexible datamodel and i'm not sure what's the right approach.
My application is used by several clients (big and small). Big clients need all the seperate layers, but small ...
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Lightweight data mining + organization & visualization
I'm looking to do some simple data mining that consists of going once per day to a single page and collect the following information:
List of movie theaters
Movies today on each theater
Session times ...
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Index / Unique on `deleted_at` column?
We have an Accounts table in a Postgres DB that has a unique index on user_id and product. Users can have many accounts, there's no product table. Occasionally users will create an account ...
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how to model 2 objects that refer to each other in the DB
Now I have 2 objects which are "PROBLEM" and "SOLUTION", obviously "SOLUTION" is a proposed solution to a given "PROBLEM", my problem is that in my business I have the following relations:
a "...
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Is there an industry standard for gender model other than male and female?
I am modeling a database that should be used as generic non-functional requisite for all services of the startup company, like persons, users, services and commercial data like coupons, signature ...
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How to model rdbms relationships as graph relationships?
I am modeling our existing database in transition to a graph database.
Currently here is how I can interpret the database a graph relationships
group -have-> groups
group -have-> participants
...
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How to store sequential timespans in a database?
How can consecutive periods of time (defined by a start and end date) be stored in a database?
For example:
from 2018-01-01 00:00:00+01:00 until 2018-06-01 00:00:00+02:00
from 2018-06-01 00:00:00+02:...
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What is an example giving the difference between Domain Model and Data Model?
I've seen many articles describing differences between Domain Model and Data Model. However none of the articles have picture representations showing difference.
https://stackoverflow.com/questions/...
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Handling guest users in ecommerce application
I'm currently developing an Ecommerce application and am trying to figure out how best to add a 'guest checkout' feature. The 3 main models that I am wrestling with to add this feature are Address, ...
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