Background I'm a novice SQL user. Using PostgreSQL 13 on Windows 10 locally, I have a table t: +--+---------+-------+ |id|treatment|outcome| +--+---------+-------+ |a |1 |0 | |a |1 |1 | |b |0 |1 | |c |1 |0 | |c |0 |1 | |c |1 |1 | +--+---------+-------+ The Problem I didn't explain myself well initially, so I've rewritten the goal. Desired result: +-----------------------+-----+ |ever treated |count| +-----------------------+-----+ |0 |1 | |1 |3 | +-----------------------+-----+ First, identify id that have ever been treated. Being "ever treated" means having any row with treatment = 1. Second, count rows with outcome = 1 for each of those two groups. From my original table, the ids who are "ever treated" have a total of 3 outcome = 1, and the "never treated", so to speak, have 1 `outcome = 1. What I've tried I can get much of the way there, I think, with something like this: select treatment, count(outcome) from t group by treatment; But that only gets me this result: +---------+-----+ |treatment|count| +---------+-----+ |0 |2 | |1 |4 | +---------+-----+ Continue reading...
