ddd-by-examples / ddd-by-examples/library

Question about DB schema

Open
#77 0 comments 0 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

Dominant language
Java
Stars
5.9k
Forks
831
PR merge metrics
No merged PRs in 30d

Description

Hi,
I am new to DDD and I am finding this repo very helpful. Just curious about the way one to many relationship between book and patron is handled in DB in lending module.
BookOnHold (book_database_entity) entity has byPatron and holdPlacedAt which is a standard way of doing one to many relationship but there is also a PatronHolds (holds_database_entity) entity which pretty much has the same information. Can someone please explain what kind of pattern this is ? Isn't this just duplicating data in DB ?

Contributor guide

No contributing guide indexed for this repository

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start by reading the BookOnHold (book_database_entity) and PatronHolds (holds_database_entity) entities in the lending module, then trace how the book–patron hold relationship is represented. Done means documenting the pattern and explaining whether the repeated information is intentional.

Written by the indexing model from the issue text.

Assessment

Tech stack
java
Domain
databases
Issue type
Documentation
Difficulty
3/5
Estimated time
1-2 days
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
25/100

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.