JPA Types

Loading Types

Eager – initialization occurs on spot.

Lazy – defers initialization as long as possible.

Cascade Types

ALL – propagates all operations.

PERSIST – propagates persist operation.

MERGE – propagates merge operation.

REMOVE – propagates remove.

REFRESH – propagates refresh and reload of children elements.

DETACH – propagates detachment to children elements.

LOCK – propagates reattachment for children in persistence context.

Mapping types

https://medium.com/@saeiddrv/jpa-hibernate-mapping-types-891686bc6cfd

Persist vs Merge

persist – to add totally new entities

merge – to put back into persistence context if the entity was detached and changed.

Detached object, is an object that has been persisted but then it’s session has been closed.

https://stackoverflow.com/questions/4509086/what-is-the-difference-between-persist-and-merge-in-jpa-and-hibernate?rq=3