Typo3 Extbase：如何按子对象的属性对父对象进行排序

Question

Say I have an extbase extension with parent objects "foo" with an m:n relationship to child objects "bar". Each "bar" object has an integer property "barNum". I want to sort my "foo" objects by which one contains a "bar" object with the lowest "barNum" value. How can I do this?

I can sort by fields of the foo object like:

class FooRepository extends \TYPO3\CMS\Extbase\Persistence\Repository
{
    protected $defaultOrderings = [
        'fooField' => \TYPO3\CMS\Extbase\Persistence\QueryInterface::ORDER_ASCENDING,
    ];
    }

But I don't see any way to sort by a field of an m:n related child object

---

To clarify: for example, if my data looks like this:

"foos": {
    "foo1": {
        "bars": {
            "bar1": {
                "barNum": 31
            },
            "bar2": {
                "barNum": 42
            }
        }
    },
    "foo2": {
        "bars": {
            "bar3": {
                "barNum": 82
            },
            "bar4": {
                "barNum": 19
            }
        }
    },
    "foo3": {
        "bars": {
            "bar5": {
                "barNum": 37
            }
        }
    }
}

I would want it sorted foo2, foo1, foo3 , because 19 < 31 < 37.

Answer 1

You can sort by sub objects and properties by using the . , eg fooFieldWithObject.barField .

In your case I'd try: bars.barNum

class FooRepository extends \TYPO3\CMS\Extbase\Persistence\Repository
{
    protected $defaultOrderings = [
        'bars.barNum' => \TYPO3\CMS\Extbase\Persistence\QueryInterface::ORDER_ASCENDING,
    ];
}