Deployd: POST update summary table

I am new to deployd.

I have a "ratings" table which basically has ID

and ratingValue

(1 to 5) I have a "ratingSummaryTable" which has ID

, ratingID

(from the ratings table) and five columnsn_rating1, n_rating2, n_rating3, n_rating4, n_rating5

I want to be able to update the pivot table when it ratings

has a new item ( onPost

) on

• creating a rating of the SummaryTable row if it doesn't exist
• incrementing the corresponding n_rating & i. (where & i is the rating).

I think this will happen in the event API, but I don't know how to do it (or even know if it is possible to do it) ...

thanks for the help