Questions tagged [datamodel]
According to Hoberman (2009), "A data model is a wayfinding tool for both business and IT professionals, which uses a set of symbols and text to precisely explain a subset of real information to improve communication within the organization and thereby lead to a more flexible and stable application environment.
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What is difference between a Model and an Entity [closed]
I am seeking clarification on the definitions of the terms Entity, Model, DataModel, and ViewModel within the context of software development. Could someone provide a detailed explanation for each of ...
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Evaluating HDF5: What limitations/features does HDF5 provide for modelling data?
We are in evaluating technologies that we'll use to store data that we gather during the analysis of C/C++ code. In the case of C++, the amount of data can be relatively large, ~20Mb per TU.
After ...
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votes
3
answers
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Column-family concept and data model
I'm investigating the different types of NoSQL database types and I'm trying to wrap my head around the data model of column-family stores, such as Bigtable, HBase and Cassandra.
First model
Some ...
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6
answers
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How / if to refactor a Delphi program using only forms and data modules
After years of coding Delphi programs as untestable code in forms and datamodules, including global variables, and the only classes are the forms themselves, containing all the code I need for the ...
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How to load just the last record from entity with LINQ?
I want to fetch value of field named "Gram" from the last record and put its value into a variable, without using any conditions.
First I tried
int value = int.Parse(Entity.TblGold.LastOrDefault()....
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8
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Data Model for Boolean Expressions
Do you know a way to organize boolean expressions in a database while allowing infinite nesting of the expressions?
Example:
a = 1 AND (b = 1 OR b = 2)
The expression as a whole shouldn't be stored ...
Sebastian
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7
answers
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How to properly delete and re-add Entity Data Model
newbie to Entity Framework here. Using VS 2010 and SQL Server 2008 express DB.
I was having trouble refreshing an Entity Data Model after adding new tables. So, I followed a suggestion I found here ...
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1
answer
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Object Oriented Database Vs object Relational Database
I wonder how Object Oriented data modeling is different from Object Relational data modeling?
Is it something like the pluses of both object oriented and relational data modeling were clubbed to ...
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2
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Angular 2 define data models for multiple modules
I'm currently starting a new project with Angular 2.0 (release Version) and I want to define some global data models/schemas. As I understand it, Angular 2 has no default way of handling pure data ...
- 509
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3
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Working with Protocol Buffers and internal data models
I have an existing internal data model for a Picture, as follows:
package test.model;
public class Picture {
private int height, width;
private Format format;
public enum Format {
JPEG, ...
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asp.net mvc models vs entity framework models
Would it be best practice to create a model in your asp.net mvc - model folder.
Use these models with your views and by using a service layer to "adapt" my model to the EF-model.
Or have you used ...
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what exactly is a map dimension in a multi-dimensional map?
Like many these days, I am an old relational-model user approaching Cassandra for the first time. I have been trying to understand Cassandra's data model, and when I read about it I frequently ...
- 3,165
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1
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Designing a data model for versioned data
I'm looking for some input on the best way to design a data model that revolves around versioned data. There will one-to-many and many-to-many relationships which can all change from version to ...
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MOMC error with XCode4 and Data Model Compile
Whenever I build my project, I'm getting the error:
Command /Developer/usr/bin/momc failed with exit code 1
I've read posts here about deleting extraneous Data Model versions as a fix, and nothing ...
- 1,242
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5
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Formatting XSD scheme for peer review
I designed a data model which is represented by an XSD scheme.
The data model also provides the types that are being used as web service parameters in a WSDL descriptor.
I would like to send the XSD ...
- 4,089
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InfluxDB data structure & database model
Can you please tell me, which data structure has an InfluxDB und which data model InfluxDB use? Is this key-value model. I read the full documentation and I didn't catch that.
Thank you in advance!
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Generate code for core data attributes in xcode 4
In xcode 3 there was a helpful feature in the data model builder where you could highlight some attributes/relationships in an entity, right-click, and choose to copy method and property declarations ...
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votes
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update/change array value (swift)
Data Model
class dataImage {
var userId: String
var value: Double
var photo: UIImage?
var croppedPhoto: UIImage?
init(userId:String, value: Double, photo: UIImage?, croppedPhoto: ...
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4
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An alternative to hierarchical data model
Problem domain
I'm working on a rather big application, which uses a hierarchical data model. It takes images, extracts images' features and creates analysis objects on top of these. So the basic ...
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Xcode Data Model Editor not appearing
I'm using Xcode 4.2 and I'm trying to use Core Data. Upon clicking the .xcdatamodeld file I see a strange view instead of the Data Model Editor View.
I have reinstalled Xcode 4.2 and have even ...
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1
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Why custom types accept ad-hoc attributes in Python (and built-ins don't)?
I'd like to know why one is able to create a new attribute ("new" means "not previously defined in the class body") for an instance of a custom type, but is not able to do the same for a built-in type,...
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1
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How does ExtendedTableDataModel reset method work? Is there documentation?
How does ExtendedTableDataModel (in RichFaces library) work after sorting or having the actual data changed? I'm asking for good quality documentation first and foremost, but also your own intelligent ...
- 4,360
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2
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difference between User and Account object in social network design? [closed]
I am building a data model for a social networking site and lost of how to model Users and Accounts.
1) User signsup and creates an Account. So we assign the User a user Id like on most social ...
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3
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Creating data model class for database handling
I was just starting to work on an database application when I realized I should implement MVC pattern as the application is quite complex and involves a number of database operations.
In regards to ...
user790431
7
votes
3
answers
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Oracle Data Modeler - Diagram notation
Is there a detailed notational guide for the Relational model diagrams generated by the Oracle Data Modeler?
I'm using Oracle Data Modeler to generate Relational Models for an existing database. It ...
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votes
2
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Useful stock SQL data models?
As a parallel to my question about Useful stock SQL datasets, I wonder if anyone has come across a library/web page/wiki/etc. that contains stock SQL data models. For example, the problem of ...
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votes
2
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Implementing a data model to prevent common errors
There seem to be multiple ways to implement data models in Clojure:
ordinary built-in datatypes (maps/lists/sets/vectors)
built-in datatypes + meta-data -- for example: (type ^{:type ::mytype} {:...
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votes
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How to maintain an ordered table with Core Data (or SQL) with insertions/deletions?
This question is in the context of Core Data, but if I am not mistaken, it applies equally well to a more general SQL case.
I want to maintain an ordered table using Core Data, with the possibility ...
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4
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How to create ASP.Net MVC DropDownList with required validation
I working with mvc 5. I am loading data from Database Using ORM and fill a drop down list from the controller, like this.
ViewBag.Country_id = new SelectList(_db.Countries, "Country_id", "Description"...
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Database/model field-name convention in Laravel?
I understand that camel case is the usual convention, as per http://forums.laravel.io/viewtopic.php?id=8857
However, Laravel is using created_at and updated_at for timestamp fields.
I'm confused as ...
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Why are coordinates of polygon GeoJSON Objects stored in an array of array?
As seen in the official documentation, structure of the polygon GeoJSON object is as shown below:
db.someCollection.insert({
type: "Polygon",
coordinates: [
[
[0, 0], [3, 6], [...
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Stucking on creating connection in model - Power BI
I connect my sql database to Power BI. I got sth like 80.000 rows and I have two additional calculated columns that get previous vales. Here is a code Table.AddColumn(#"Added Custom", &...
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Best practice for storing GPS data of a tracking app in mysql database
I have a datamodel question for a GPS tracking app. When someone uses our app it will save latitude, longitude, current speed, timestamp and burned_calories every 5 seconds. When a workout is ...
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4
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Why do Excel sheets have to be activated before selection?
This code
Sheets(1).Activate
Sheets(2).Range("A1").Select
will fail in VBA because you can only use Select on an object which is Active. I understand this is the case.
What element of the Excel ...
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How to handle additional columns in join tables when using Symfony?
Let's assume I have two Entities in my Symfony2 bundle, User and Group. Associated by a many-to-many relationship.
┌────────────────┐ ┌────────────────┐ ┌────────────────┐
| ...
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Programmatically adding table to Microsoft SQL Server Compact 3.5 Database
We want to add a table programmatically to our local stored Microsoft SQL Server Compact 3.5 Database. The code below creates the table.
using (SqlCeConnection con =
new SqlCeConnection("...
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votes
2
answers
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Data Modeling: Supertype / Subtype
Looking to figure out the proper way to model the below requirements.
There are 3 types of “parties” to be concerned with, a Fan, a Band, and a BandMember.
That BandMember will always be associated ...
- 1,765
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votes
1
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Qt QML data model doesn't seem to work with C++
I've been working with the examples in http://doc.qt.digia.com/4.7/qdeclarativemodels.html which is the Qt page on QML declarative data models. In particular, I'm working with the objectlistmodel ...
- 7,076
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How to create an ElasticSearch Type and make it searchable inside the Index
I'm an iOS Swift developer and I'm using ElasticSearch inside my app. I'm trying to wrap my head around how to declare a type in ES , what's the difference between a type and document, and which is ...
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Best Practice: Should one avoid bi-directional relationships? [closed]
I wonder what the best practice is to deal with a data model like this:
We have 3 entities:
Role
User
Permission
Note that the entities are represented as java classes and will be mapped to a ...
- 6,770
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votes
1
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__getitem__, __setitem__ multiple keys
I am trying to create a class that stores data in a local buffer as well as acts as an interface to a database. I've got following code:
class Table(object):
def __init__(self, tableName, **...
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Modelling Access Control in MongoDB
Does anyone have an example of modelling access control in MongoDB? The situation I'm thinking of is:
There are a set of resources, each being their own document (e.g. cars, people, trees etc.).
A ...
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1
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Haskell Data Model Visualization from Source
Is there a tool that will automatically create a visualization (a class diagram sort of thing) of a haskell data model from source code? Something that walks down data constructors and records and ...
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1
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Custom fields in Rails that act as a template for future entries
I'm looking for some feedback on my current plan of implementing custom fields in rails. I'm new to rails and app development in general and would appreciate any comments from more experienced ...
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Excel Data Model without using PowerPivot
I have a question about the "Data Model" in excel. Whenever I read about this function, it is used with PowerPivot.
I ask because I would like to do something like this:
I have table A:
ID
info1
...
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Jsf DataModel vs Java List problem ( no row available exception )
In JSF 1.2 One was listing Items using Java List :
private List<Customer> customerItems = null;
, but in JSF 2.0 JSf DataModel (ListDataModel) is the way to go. (I am using JSF 2.0)
private ...
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1
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Is it possible to send more than one model object to an ASP.NET MVC View?
On my start page, I'd like to display the first items from several different lists that I have on other pages - somewhat like the "recent" page here on SO displays both recent posts and recent ...
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4
votes
2
answers
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Convert array data model to dictionary (swift)
Data Model
class DataCart {
var icon: UIImage?
var cartId: String
var price: Int
var productName: String
var quantity: Int
init(icon: UIImage?, cartId: String, price: Int, productName:...
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votes
4
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Converting xml schema to relational model
Do you guys know, how we can convert XML Schema to relational model? What are the steps involved?
More precisely, How can we figure out what the table names, columns names and the relationships on ...
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