What are the consequences of disabling relation generation in the JOOQ generator?

Question

I can disable identity, foreign key, and unique key generation in the JOOQ generator by setting the following configuration options :

<generate>
  <!-- Primary key / foreign key relations should be generated and used.
       This is a prerequisite for various advanced features.
       Defaults to true -->
  <relations>false</relations>

Despite the FK/UK information not being present in the meta-model, what exactly are the consequences of disabling this generation? Which features of JOOQ itself depend upon this information?

Answer 1

Essentially, most of the features documented in the manual's section about CRUD will be unavailable to you:

http://www.jooq.org/doc/latest/manual/sql-execution/crud-with-updatablerecords/

Primary keys

Without knowledge about primary keys, there are no UpdatableRecord . Ie, you will not be able to write things like:

// This works:
MyTableRecord record =
DSL.using(configuration)
   .selectFrom(MY_TABLE)
   .where(MY_TABLE.ID.eq(1))
   .fetchOne();

// These won't work:
record.store();
record.update();
record.refresh();
record.delete();

// This will still work:
record.insert();

Foreign keys

Foreign key information is currently used in only a few places in jOOQ, among others, navigation methods :

BookRecord book = DSL.using(configuration)
                     .selectFrom(BOOK).where(BOOK.ID.eq(1)).fetchOne();

// This won't work
AuthorRecord author = book.fetchParent(FK_BOOK_AUTHOR);

There are also plans to enhance the code generator to generate such navigation methods ( #4210 ), which means that the following won't work:

// This won't work
AuthorRecord author = book.fetchFkBookAuthor();

Or, the synthetic JOIN ON KEY clause:

DSL.using(configuration)
   .select()
   .from(AUTHOR)
   .join(BOOK).onKey()
   .fetch();

There will be other features depending on the availability of constraint information in the future, but ordinary SQL statements aren't affected.