I’m trying to do a simple calculation in my rails project. I would like
to find all rows in a table that match the given id of another table
(ie. comment_id) and has the value = 1 (“value” is a field in the
table), then add those values up. Next find the same rows with the
value = -1 and add those values up also. Finally, I would like to find
the total. Therefore, if there were 5 rows with value = 1, this would
be 5 and 3 rows with value = -1, this would be -3. Then when I add them
together, it would be totalvalue = 2.
Would somebody be able to help me with this? Or is there a better way to
do this? I’m not exactly sure where and how to setup this (do I do this
in the model or controller?).