Available in versions: Dev (3.19) | Latest (3.18) | 3.17 | 3.16 | 3.15 | 3.14 | 3.13 | 3.12 | 3.11 | 3.10 | 3.9
This documentation is for the unreleased development version of jOOQ. Click on the above version links to get this documentation for a supported version of jOOQ.
NATURAL clause
Applies to ✅ Open Source Edition ✅ Express Edition ✅ Professional Edition ✅ Enterprise Edition
All of INNER JOIN, OUTER JOIN, SEMI JOIN, ANTI JOIN require a join predicate.
One way to supply this join predicate is the NATURAL clause, which works like USING clause, except that it discovers shared column names implicitly from the table metadata. Assuming we called our AUTHOR.ID column AUTHOR.AUTHOR_ID instead:
SELECT * FROM AUTHOR NATURAL JOIN BOOK
create.select()
.from(AUTHOR)
.naturalJoin(BOOK)
.fetch();
There is a high risk of ambiguities even in simple join trees, which is why this syntax is hardly ever used. It can be very rarely useful combined with FULL JOIN to form a NATURAL FULL JOIN, which can create a sort of SQL-style untagged union type between two row types. A bit esoteric for every day usage.
Feedback
Do you have any feedback about this page? We'd love to hear it!