Spring Boot Persistence Best Practices: Optimize Java Persistence Performance in Spring Boot Applications

© Anghel Leonard 2020

A. LeonardSpring Boot Persistence Best Practiceshttps://doi.org/10.1007/978-1-4842-5626-8_5

5. Collections

Anghel Leonard¹ 

(1)

Banesti, Romania

 

Item 56: How to JOIN FETCH an @ElementCollection Collection

Especially when defining a unidirectional one-to-many association to a Basic type (e.g., String) or Embeddable type, JPA has a simple solution in the form of @ElementCollection. These types are mapped in a separate table that can be customized via @CollectionTable . Let’s assume that an online bookstore shopping cart is mapped via the ShoppingCart entity and the embeddable Book is mapped via @ElementCollection, as shown in Figure 5-1.

Figure 5-1

The @ElementCollection table relationship

The relevant part is the @ElementCollection ...