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Implicit JOIN
Applies to ✅ Open Source Edition ✅ Express Edition ✅ Professional Edition ✅ Enterprise Edition
One of HQL's greatest features is the implicit JOIN feature, which is generated from path expressions when you follow foreign key "paths" from child entities to parent entities. The same feature is available in jOOQ as well, if you're using code generation.
In HQL, you might write:
from Book as book where book.language.cd = 'en'
And in jOOQ, this just translates to:
create.selectFrom(BOOK)
.where(BOOK.language().CD.eq("en"))
.fetch();
Some of the jOOQ features used in this section are:
- implicit joins (these are optional to the task of nesting, but greatly simplify it)
In Hibernate, implicit joins always produce anINNER JOIN, which may be surprising on nullable foreign keys, or onto-manypath navigations. jOOQ generatesLEFT JOINby default, though you can override this behaviour with Settings.
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