All we need is an easy explanation of the problem, so here it is.
I have a table, action using postgresql:
is_jump | is_throw | is_punch true true false false true false false true true
These are all booleans.
I want to get a count for each of the actions (when true) into one result table in one query:
is_jump_count | is_throw_count | is_punch_count 1 3 1
I can get the count for one of them at the time, that’s the easy part, but, how can I combine it all in one query so that I get one result table with the counts by column like shown here?
I have implemented it this way, but, I wonder if there’s a better way to accomplish this given that in the end I think I’ll end up with about 15 actions to track count for…:
SELECT a.ct is_jump, b.ct is_throw FROM ( SELECT COUNT(*) ct FROM action WHERE is_jump=true and user_id=6 ) a, ( SELECT COUNT(*) ct FROM action WHERE is_throw=true and user_id=6 ) b;
How to solve :
I know you bored from this bug, So we are here to help you! Take a deep breath and look at the explanation of your problem. We have many solutions to this problem, But we recommend you to use the first method because it is tested & true method that will 100% work for you.
You can use filtered aggregation:
select count(*) filter (where is_jump) as is_jump_count, count(*) filter (where is_throw) as is_throw_count, count(*) filter (where is_punch) as is_punch_count from the_table;
Note: Use and implement method 1 because this method fully tested our system.
Thank you 🙂