In Parse Server, say I have School class, which has courses relation. as shown in the picture
What I want here is to get all schools including the courses relation. BUT, it should NOT include all columns of Course class. only objectId column.
Reason: for performance. I want to get all schools with courses ids of every school, to count them. If i loaded the whole Course object, the query maybe gets slow.
This is my code:
// create query
let query = PFQuery(className:"School")
query.includeKey("Courses")
query.limit = 50
query.cachePolicy = PFCachePolicy.networkElseCache
query.findObjectsInBackground { (objects: [PFObject]?, error)-> Void in
if error == nil {
// The find succeeded.
print("Successfully retrieved \(objects!.count) school.")
// TODO: get courses count
} else {
// Log details of the failure
print("Error: \(error!) \(error!)")
}
}
So, I need to get the courses count of every school without loading the whole course objects, only loading objectIds of courses, to make the query super fast
Thanks
