The best way to map a @OneToOne relationship with JPA and Hibernate
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- Опубліковано 2 жов 2022
- In this video, we are going to learn the best way to map a @OneToOne association with JPA and Hibernate.
While there are many ways you can map a one-to-one relationship with Hibernate, I’m going to demonstrate which mapping is the most efficient one from a database perspective. - Наука та технологія
Today I have heard about you from my colleague, and I fell in love with your articles and now I am very glad to see you here. Thanks in advance))
Thanks and stay tuned for more
Awesome content as always, keep up the good work!
Thanks, Piotr. Stay tuned for more!
Hello @Vlad, this video is perfect! It's a complex topic but your explanation is so good. Thanks a lot.
I'm glad you liked it and stay tuned for more
Excelent video, it was so helpful. Thanks!
You're welcome
very good lecture, many tks!
You're welcome. If you liked this snippet, you are going to love the video course where this snippet is coming from:
vladmihalcea.com/courses/high-performance-java-persistence/
Thanks for the great video, as always. Could you please share what visualization tool you are using at 0:45?
The class diagrams were generated with IntelliJ IDEA.
The DB table diagrams with MySQL Browser.
The rest of the diagrams were generated with yEd.
Perfect. A video series would definitely be a great add-on for all the hibernate blogs you've written
This video is an episode of the 11-hour video course, High-Performance Java Persistence.
So, if you enjoyed this video episode, you are going to love this video course:
vladmihalcea.com/courses/high-performance-java-persistence/
Great video! Now, I'm thinking about whole course :) please, tell me why children entity should be owning side of relation?
I'm glad you liked it. In fact, you are going to love the video course even more.
As for your question, the entity that maps the FK column is the one that should own the relation because FK column values are supposed to be managed via their associated table record.
Video sound is low.
Btw good explanation.
On my latest videos, I increased the volume.
why do i need to have a one to one relationship? I mean i can wrap the details or include it in the post table
That's a very good question that I frequently get during my training. The @OneToOne relationship basically maps the one-to-one table relationship that was designed 40 years ago and which serves plenty of use cases, like the following ones:
- if you have a JSON column that's large, you might not want to fit it on the same page as the original record as that could create page splits, increase the volume of data that gets synced to the disk when the pages get dirty
- if you have columns that have different change frequencies, you can split them by write access patterns so that you could have the columns that frequently change in a separate table whose pages get synced often, but they leave the other table pages to reside in the Buffer Pool
- to implement the JOINED table inheritance strategy
- to split a large table into multiple ones to increase write scalability as UPDATEs and DELETEs take locks at record level in relational databases, and once you change a single column, the entire record gets locked until you commit or roll back. But by splitting the original table into several tables, you can increase the write throughput.
- to reduce the optimistic locking conflicts as you have multiple version columns in multiple tables. If you only have a single table, then any column change will cause the other concurrent transactions that also want to change the same record to abort after the first transaction has bumped the version up.
Why not make a Post as a relation owner?
Why would I do that?
How can we achieve this feature in spring data jpa?
Which feature are you talking about?
@@vladmihalcea I mean one to one relationship without n+1 problem which you described in video
@@aleemkhowaja2274 The solution for that can be done with a Maven or Gradle plugin that it's independent of Spring. So, it works I the same way with Spring as it does with Java EE.
@@vladmihalcea ahh ok yaah makes sense to me thanks bro btw great explanation in video and thank you so much for response cheers 🥂 🙂
@@aleemkhowaja2274 You're welcome. If you liked this video, there's a 40% discount on the video course:
vladmihalcea.teachable.com/p/high-performance-java-persistence-mach-3-online/?coupon_code=BLACKFRIDAY22
But hurry up! It expires in 2 days.