Hibernate: Set beats List for a @OneToMany you modify

A List with a join table is deleted and reinserted wholesale on any change; a Set updates the row that changed.

Code

// Deletes all rows and reinserts on every change:
@OneToMany @JoinTable(...)
List<Tag> tags;

// Updates just what changed:
@OneToMany @JoinTable(...)
Set<Tag> tags = new HashSet<>();

Output

List: delete from order_tags where order_id=?;  then 20 inserts
Set:  insert into order_tags values (?, ?)      just the new one

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Published 2026-08-11