21/10/02(토) JPA 스터디 자료입니다. Covenant: https://github.com/KoEonYack <><

1. JPA
Covenant
Chapter 5
JPA
JPQL Join Fetch

2. - Name. Covenant Ko
- Company. 11번가
- Github 용감한친구들 Organization Founder & Maintainer. https://github.com/brave-people
- Github. https://github.com/KoEonYack
- Tech Blog. https://covenant.tistory.com/ (누적 방문 51만)

3. (Cartesian Product)
JPQL Fetch Join ?
https://www.mathstopia.net/sets/cartesian-product
A×B = { (a,b) | aϵA and bϵB }
Cartesian Product is the multiplication of two sets to
form the set of all ordered pairs.

4. (Cartesian Product)
JPQL Fetch Join ?

5. 1
1
1 *
1
*

6. 1
1
1 *
1
*

7. 1
1
1 *
1
*

8. 1
1
1 *
1
*
Order Member Delivery

9. 1
1
1 *
1
*
Order Member Delivery
?

10. 1
1
1 *
1
*
Order Member Delivery
?
.

11. 1
* 1
1
1
* *
1

12. 1
* 1
1
1
* *
1
DB Order 2 OrderItem 2 ?
OrderA
OrderA
OrderB
OrderB
OrderItemA
OrderItemB
OrderItemA
OrderItemB

13. Distinct
1. SQL distinct row .
2. JPQL distinct Root Entity

14. Distinct
1. SQL distinct row .
2. JPQL distinct Root Entity
? No

15. Distinct
1. SQL distinct row .
2. JPQL distinct Root Entity
?

16. Distinct
1. SQL distinct row .
2. JPQL distinct Root Entity
? No

17. Distinct
1. SQL distinct row .
2. JPQL distinct Root Entity
? No

18. ?
https://velog.io/@neity16/

19. ?
https://velog.io/@neity16/
DB JPQL DISTINCT

20. 1. ToOne(OneToOne, ManyToOne)
2.
3. hibernate default_batch_fetch_size or @BatchSize

21. JPA
Covenant
Chapter 5
JPA
JPQL Join Fetch