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Questions tagged [data-modeling]

Data modeling questions refer to the techniques used to gather and analyze data requirements needed to support data operations in programs and systems.

Data modeling consist of gathering requirements and knowledge about the data needed to solve a given problem, and elaborating abstract data structures for the purpose of designing and implementing standardised data formats, databases and data processing systems.

Data-modeling is a specialized kind of modeling solely focused on passive data structures, and independent of the description of the processing of that data.

3039 questions
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Xcode consistency error: Setting the No Action Delete Rule... is an advanced setting

After creating a data model in Xcode, it's throwing the following error for each of the object relationships: Consistency Error: Setting the No Action Delete Rule on [object relationship] is an advanced setting What is Xcode trying to tell me, and…
Dan
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What's the difference between data model and object model?

CWM is data modeling UML is object modeling. Can someone explain the difference that a layman can understand?
user198729
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Determine Event Recurrence Pattern for a set of dates

I am looking for a pattern, algorithm, or library that will take a set of dates and return a description of the recurrence if one exits, i.e. the set [11-01-2010, 11-08-2010, 11-15-2010, 11-22-2010, 11-29-2010] would yield something like "Every…
calstad
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Relational vs Non-Relational Data Modeling

I have a user database with the following properties for each user: user id name zip city In a relational database I would model it in a table user: user id name location_id and have a second table called location: location id zip city and…
znq
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Database constraints - keep or ignore?

When I was learning in university, they taught us the database fundamentals, basics and rules, and one of the most important rules is the constraints (primary key, foreign key), and how to make 1-m, 1-1, m-n relationships. Now when I move to real…
Anyname Donotcare
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Tools to generate a database diagram/ER diagram from existing Oracle database?

Looking for tools (windows platform) to genereate ER diagram (or similar) from an existing Oracle database. Any good tools out there that are free to use or low cost?
Kb.
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How to model Student/Classes with DynamoDB (NoSQL)

I'm trying to get my way with DynamoDB and NoSQL. What is the best (right?) approach for modeling a student table and class tables with respect to the fact that I need to have a student-is-in-class relationship. I'm taking into account that there is…
Chen Harel
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MySQL friends table

I have a MySQL DB in which I store data about each user. I would like to add a list of friends for each user. Should I create a table of friends for each user in the DB or is there a better way?
user356178
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Handling incremental Data Modeling Changes in Functional Programming

Most of the problems I have to solve in my job as a developer have to do with data modeling. For example in a OOP Web Application world I often have to change the data properties that are in a object to meet new requirements. If I'm lucky I don't…
Adam Gent
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How to Model a "likes" voting system with MongoDB

Currently I am working on a mobile app. Basically people can post their photos and the followers can like the photos like Instagram. I use mongodb as the database. Like instagram, there might be a lot of likes for a single photos. So using a…
user2914635
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Django multi-table inheritance alternatives for basic data model pattern

tl;dr Is there a simple alternative to multi-table inheritance for implementing the basic data-model pattern depicted below, in Django? Premise Please consider the very basic data-model pattern in the image below, based on e.g. Hay, 1996. Simply…
djvg
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What ways are there to store information about an anonymous/guest user in a database?

Our application has an online shop among other features, and users are normally requested to register before completing a sale, creating a unique customer_ID in the process. When they return, they can log in and their contact details and transaction…
boatingcow
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Cassandra data model for simple messaging app

I am trying to learn Cassandra and always find the best way is to start with creating a very simple and small application. Hence I am creating a basic messaging application which will use Cassandra as the back-end. I would like to do the…
user2924127
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Choosing a partition key for a Cassandra table -- how many is too many partitions?

I have an application where the 'natural' partition key for a Cassandra table seems like it would be 'customer'. This is the primary way we want to query the data, we would get good data distribution, etc. But if there were well over 1 million…
Kevin Bedell
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How to properly cascade delete managed objects in Core Data?

I have a Core Data model which has three entities: A, B, and C. A has a one-to-many relationship with B, and B has a many-to-many relationship with C. The delete rule for A -> B is "Cascade", and B -> A is "No Action". The delete rule for B -> C is…
CJ.
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