Get Total count (one number) for all RelatedData from different rows

Android
1

Hello
Let’s say I have have a Videos table and column (1:N) called LikedBy. this column is a relationship to the user table. Essentially the Videos table list all videos posted by all users and each video is liked by many users.

What I am trying to get is to get ALL the likes that a poster (user) received for his videos.
Therefore a user might have 4 videos and each video is liked by 2 users (can be the same users) then the total count would be 8

One way to do that is to do a query that will get me count of related data grouped by videoID and the where clause will specific the poster objId. The downside is that I have to iterate in code through all the results to add the counts up (which might have paging overhead on top).

Is there a shortcut way that can get me the total count? Maybe somehow by going through the opposite direction (count the users who has a like relationship to, coming from video whose poster is xyz)? I don’t know maybe another method I am skipping.

I just don’t want to overcomplicate things if there is a shortcut

Thank you so much for your support today in this.

2

If you already have some test data in your app, please share your app ID so we can play with a query to make a suggestion.

Regards,
Mark

3

Hi Mark
Here is the App ID 40A7AC6F-A4BF-02C0-FFBD-1EEC13921300
The poster objId is CA7E0DE6-0103-37C9-FFE6-FEB6BFDE7F00 that I want to get count of all “DisLikes”

Use dislikes column as it has better test data

4

Here’s a query that does that:

curl -X GET 'https://api.backendless.com/40A7AC6F-A4BF-02C0-FFBD-1EEC13921300/YOUR-REST-API-KEY/data/Videos?where=postedBy%20%3D%20%27CA7E0DE6-0103-37C9-FFE6-FEB6BFDE7F00%27&props=COUNT(disLikedBy)

The key elements are:

  • where clause : postedBy = 'CA7E0DE6-0103-37C9-FFE6-FEB6BFDE7F00'
  • requesting an aggregate function COUNT in the props variable: props=COUNT(disLikedBy)
5

Thank you so much. I see now. If we add the groupBy then it does it for every every video, but without groupby then it does it for all. Thank you