Hi, I’m new to MongoDB 4.x and got stuck.
I’m using the PHP 8 MongoDB extension.
This is the document structure:
Now I would like to group all questions so I only get the unique questions.
This is the code that I use:
$cursor = $collection->aggregate([
[ ‘$match’ => [ ‘account_id’ => 1005, ‘survey_id’ => 205244]],
[ ‘$unwind’ => ‘$answers.question’ ],
[ ‘$group’ => [’_id’ => ‘$answers.question’] ]
This however doesnt return any results. Also if I only unwind on $answers it doesnt work.
if I just use $answers on the unwind and group I do get back results, but they are not grouped/unique questions and questions only. So the group doesnt work and I should only get the questions back, not the answers. Thanks in advance!