Closed michaelpeterlee closed 4 years ago
It is tricky. If you look at your MongoDB database, you will see that your local field is actually _p_user
and it does not have the plain id, but something like _User$objectId
. So you will need something like this:
$query = new ParseQuery("UserActivity");
$pipeline =
[
'project' =>
[
'user' =>
[
'$substr' =>
[
'$_p_user', 6, -1
]
]
],
'lookup' =>
[
'from' =>"_User",
'localField'=> "user",
'foreignField' => "_id",
'as' => "user"
],
];
$aArticle = $query->aggregate($pipeline);
print_r($aArticle);
It is for sure something that could be better documented.
Thank you and I hope it helps someone else.
I tried that config to no-avail, however have now referred this for NodeChef to advise, as I can't peer into MongoDB easily.
Maybe I translated something wrong from "mongodb" to PHP, but I've just successfully run this query directly in MongoDB in the case it helps you:
db.AnotherClass.aggregate([{$project:{user:{$substr: [ "$_p_user", 6, -1 ]}}},{$lookup:{from:'_User',localField:'user',foreignField:'_id',as:'user'}}])
MongoDB >= 3.2 is required. Without that I receive a blank response.
With that upgraded, 'lookup' stage is now working.
I had to engage a Parse string column for localField, rather than a Parse pointer for it to work. The 'project' stage your supplied did not work for me, I just omitted for now.
$pipeline = [ 'lookup' => [ 'from' =>"_User", 'localField'=> "userObjectId", 'foreignField' => "_id", 'as' => "user" ], ];
Thanks very much for your help; This is a wonderful project suite to enable a turnkey, scalable API!
Issue Description
Can we please have some docs to demonstrate aggregate(pipeline) in context of joining _User table.
No matter what I do, I always get an empty resultset.
Steps to reproduce
No results exist for aggregate with pipeline lookup stage, below.
I have tried every combination of values for the lookup, including 'objectId','User', referencing pointers and strings, to no-avail.
Schema:
_User UserActivity [objectId,userObjectId,user]
I successfully apply group and project stages, just not lookup!
-
$query = new ParseQuery("UserActivity");
$pipeline = [ 'lookup' => [ 'from' =>"_User", 'localField'=> "user", 'foreignField' => "_id", 'as' => "user" ], ];
$aArticle = $query->aggregate($pipeline);
print_r($aArticle);
-
Environment Details