Questions tagged [aggregate]
An aggregate is either a group of related objects/data or the result of some operation on such group. The tag can be used for example for language specific data structures, algorithms that combine data and GROUP BY queries, UML relationships, or DDD aggregates that combine dependent objects.
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How could I map a complex DTO to a Domain Aggregate in a Repository?
I'm working on a TypeScript application designed with DDD and using layered architecture. My infra layer has a repository that fetches a complex, nested DTO. My current implementation maps this DTO ...
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Modeling invariants that requires data from multiple aggregates
I want to model the organizations and users using DDD. I have the following aggregate roots:
Users
Can join multiple organizations
Can join at most 100 organizations
Can only be deleted when it is ...
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storing aggregates as json in postgresql all in one table
I am trying to decide what the best way of storing my data would be. I want to build a cqrs application where I also apply DDD principles like aggregates in the command side. I started with with ...
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Aggregate design for a fuel tank with deliveries and fill level readings
So I've got a rather simple, mostly crud application I want to use DDD with, to learn/practice it. I wonder about aggregate design regarding a fuel tank entity. Each tank stores fill level readings (...
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Pattern / Architecture to implement State Machine with "steps" between states
I'm looking for some guidance implementing the following problem:
We have a set of 'states' which a user can enter into:
1.- Registered: A user registers themselves in the system and can start placing ...
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Unique Checks in Aggregates vs Database
I'm new to DDD and wondering what the best practice is to handle simple unique constraints.
My application allows for creation of an Item that is named by the user - and this name must be unique ...
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DDD - Managing Relationships between Domain Aggregates
To understand DDD better, I am trying to create the Domain Layer of an online class application. I have a concept of a Student, Tutor and Session.
I thought of having one aggregate called Session and ...
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Avoid updating multiple Aggregates in Library Application
I am currently analysing the project ddd-library which is really helping in learning designing a system based on DDD principles. However there is one thing I have a problem with.
In case of placing a ...
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What are the DDD aggregates in package delivery system?
I'm trying to model a specific domain using DDD techniques and have some doubts. To better contextualize, a brief description:
It's a domain of deliveries and delivery confirmation. We have two main ...
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Child Entity or Aggregate Root?
I have to design a part of a system in responsible for creating tickets for attractions and then sell them. Basically there are
three different parts:
Product: to create the tickets for sale for each ...
user161357
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When designing aggregates, can a child entity store another aggregate root ID?
I’m currently trying DDD with establishments’ opening hours:
OpeningHours is an aggregate root; it ensures its openings don’t overlap
an Establishment can be set many opening hours (like summer’s, ...
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Can two different kind of aggregates in Domain Driven Design have actually the same unique Id?
Assume that we are doing aggregate design for a ride hailing application and we have created the following aggregates: DriverAvailability aggregate, which has a value object containing the status (...
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Event sourcing, bulk update and storing multiple events vs one event with multiple ids
Event-sourcing often implies to have one row per aggregate id :
event_id
event_type
entity_type
entity_id
event_data
102
OrderCreated
Order
101
{...}
103
OrderUpdated
Order
101
{...}
This is perfectly ...
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Avoiding modification of multiple aggregate roots in one transaction
I'm modelling a scheduling application and wonder how it could be avoided to update multiple aggregate roots (AR) in one transaction. I understand the fundamental problem of changing multiple ARs in ...
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What if a Repository needs to apply Business Logic to load an Aggregate?
I have an aggregate User and the user has a Score. The Score of a user is calculated by queriying a bunch of different tables and running through (often very large) result sets applying some business ...
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