Doctrine: addSelect method creates undesired seperate object (Symfony) - mysql

Question

I want to query the entity based on a calculated property that does not exist in the database or on the entity.
If I run
return $this->createQueryBuilder('b')
->select('b')
->addSelect(
'... as extra_property'
)
->having('extra_property = :param')
->setParameter('param', $param)
->orderBy('extra_property', 'ASC')
->getQuery()
->getResult();
This results in a collection with each entity in the following format:
"0": {}, // The 9 entity properties
"extra_property": "value"
However, I want the extra_property to be added to the other entity properties as the tenth property. How do I fix this?

Answer 1

The problem lies in the getResult() method, the default hydration method is "HYDRATE_OBJECT" which will try to hydrate the output as the defined entity, which does not know about your extra property.
public function getResult($hydrationMode = self::HYDRATE_OBJECT)
{
return $this->execute(null, $hydrationMode);
}
Depending on what your other properties are, you could just use the "HYDRATE_SCALAR" option which will just give you a flat output of the results.
If you other properties are nested entities, you will have to manually select the fields in your select to bypass the hydration process, or find a way to add that property to your entity and tell the hydrator to get that data from a dedicated query or something.
You can find the different hydration methods as constants of the AbstractQuery class, you can read more on the Doctrine documentation
/**
* Hydrates an object graph. This is the default behavior.
*/
public const HYDRATE_OBJECT = 1;
/**
* Hydrates an array graph.
*/
public const HYDRATE_ARRAY = 2;
/**
* Hydrates a flat, rectangular result set with scalar values.
*/
public const HYDRATE_SCALAR = 3;
/**
* Hydrates a single scalar value.
*/
public const HYDRATE_SINGLE_SCALAR = 4;
/**
* Very simple object hydrator (optimized for performance).
*/
public const HYDRATE_SIMPLEOBJECT = 5;
/**
* Hydrates scalar column value.
*/
public const HYDRATE_SCALAR_COLUMN = 6;