In ZF1, Zend_Db_Table_Row_Abstract provides methods such as findParentRow(), findDependentRowset(), etc. These methods can be used to retrieve row objects from linked tables using a $ruleKey specified in the $_referenceMap of the corresponding table class.
What are the equivalent methods in ZF2? Could it be that this functionality is still missing?
Such things do not exist anymore. Zend Framework in its second version went back one step from providing full ORM possibilities and rather provided a good QueryBuilder. I.e. everything under
\Zend\Db\Sql\*If you want ORM-Features, you’re best advised to use a great ORM. There are a few really good ones out there, including Propel and Doctrine2. The later one already enjoying a great implementation into Zend Framework 2 via the Module doctrine/DoctrineORMModule.
Using a full ORM has many advantages with one being the awesome Documentation both Propel and Doctrine provide. Doctrine also provides compatibility with mongoDB. So you may want to give one of those a try 😉