The Query Object
Queries at the ODM layer are encapsulated in the Query
object. This
object is generated by the QueryBuilder
and is the object which mediates the transformation of queries to results.
Build a query with the query builder and execute it:
$ qb = // create a new query builder instance
$ qb->where($qb->expr()->eq('foo', 'bar'));
$ query = $qb->getQuery(); // return a new Query object
$ results = $query->getResult(); // get the results of the query
Once you have retrieved this class from the query builder it is ready to go, you have multiple ways for retrieving your data.
Getting single results
getSingleResult
Returns a single result using the given hydration mode, if
no results are found, or if the number of results exceeds one it will throw a QueryException
:
use Doctrine\ODM\PHPCR\Query\QueryException;
$ query = // get query
$ query->setMaxResults(1); // remember we get an exception if there is more than one
try {
// default action is always to return a Document
$document = $query->getSingleResult();
} catch (QueryException $e)
// no result or non unique result
}
// we can specify an alternative hydration mode if we want
$ node = $query->getSingleResult(Query::HYDRATE_PHPCR)
We should be providing seperate exception types for NoResult and NonUniqueResult respectively. QueryException can also mean "Hydration Mode not implemented"" for example. |
getOneOrNullResult
Either returns a single result or returns NULL
using the
given hydration mode
Getting multiple results
getPhpcrNodeResult
Returns all results for the query in PHPCR node format,
this method is a proxy for getResult(Query::HYDRATE_PHPCR)
.
execute
This method is the base method for all other retrieval methods. It is equivalent to the getResult method, but allows you to specify an array of parameters as the first argument:
$ query = // get new query
$ docs = $q->execute();
// is equivalenet to
$ query = // get new query
$ docs = $query->execute([], Query::HYDRATE_DOCUMENT);
At time of writing parameters are not yet supported in the ODM. |
Hydration modes
Currently the Query
object allows you to retrieve data in two formats, raw
PHPCR nodes and ODM Documents. The later being the default.
The hydration mode is specified by the use of the Query::HYDRATE_*
constants:
use Doctrine\ODM\PHPCR\Query\Query;
// HYDRATE_DOCUMENT
$ document = $query->getSingleResult(Query::HYDRATE_DOCUMENT); // the default mode
$ document->getSomething();
// HYDRATE_PHPCR
$ node = $query->getSingleResult(Query::HYDRATE_PHPCR);
$ node->getProperty('my_property_name');
In the future we will also enable the retrieval of results in Array format. |
Limiting results
The Query
object allows you to specify the maximum number of results
that should be retrieved, and also the record index from which the results
should be retrieved:
$ query = // get query
$ query->setMaxResults(100);
$ res = $query->getResult(); // will return a maximum of 100 results
$ query = // get query
$ query->setOffset(50);
$ query->setMaxResults(150);
$ res = $query->getResult(); // will return a maximum of 100 results from result index 50