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After the deletion of some data the Oracle Magazine catalogs do not get listed:
Modifying the fetch strategy
We have used the default fetch strategy in the preceding example. The default fetch
strategy for OneToMany and ManyToMany relationships is LAZY . With LAZY fetching,
the containing entities are not fetched when the contained entity is retrieved.
Therefore, we were not able to retrieve all the editions for a catalog, all the sections
in an edition, and all the articles in a section. We just listed all the catalogs, editions,
sections, and articles. With EAGER fetching, the entities contained by an entity are
immediately fetched. Next, we shall modify the fetch strategy to EAGER in the @
ManyToMany and @OneToMany relationship mappings. The fetch strategy is set with
the fetch element. In the Catalog entity replace:
@ManyToMany(cascade=CascadeType.ALL, fetch=FetchType.EAGER)
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