Cakephp 3: how to restrict a query by its contained model - cakephp-3.0

Question

I have three associated models, Clients has many Preinvoices and belongs to one Group. I would like to limit my query on Clients to only those who have associated Preinvoices (after applying conditions, see below).
Here is the outline of what I am doing (I think you can ignore the Groups part).
$clients = $this->Clients->find()
->order(['Groups.name' => 'ASC'])
->contain('Groups');
$clientPreinvoiceConditions = [
'Preinvoices.last_processed <' => $cutOffDateTime,
];
$clients->contain('Preinvoices', function (\Cake\ORM\Query $q) use ($clientPreinvoiceConditions) {
return $q
->where($clientPreinvoiceConditions);
});
So far so good – I am getting a full client list with Preinvoices matching the conditions. However it would be much better only getting Clients that in fact have any Preinvoices.
I would like to do something like:
$clients->having(['COUNT(Preinvoices.id) >' => 0]);
But this doesn't seem quite right. I get the error:
Unknown column 'Preinvoices.id' in 'having clause'
This, by the way, is despite the fact that I do get a Preinvoices.id in the result.
I also tried to first select the count as its own column so that I could reference this in having(), but no success:
$clients->select([
'preinvoiceCount' => 'COUNT(Preinvoices.id)'
]);
This gives me the error:
Unknown column 'Preinvoices.id' in 'field list'
Complex queries in Cake always seem to stump me. Ideas?

Answer 1

As pointed out by ndm's comment, the problem is very similar to the one solved here:
How to filter by conditions for associated models?
In my particular case it means changing my 'contain' to a 'matching', AND also adding a normal 'contain', like this:
$clients->matching('Preinvoices', function (\Cake\ORM\Query $q) use ($clientPreinvoiceConditions) {
return $q
->where($clientPreinvoiceConditions);
});
$clients->contain('Preinvoices');