I'm looking to filter out rows in the database (PostgreSQL) if one of the values in the status column occurs. The idea is to sum the amount column if the unique reference only has a status equals to 1. The query should not SELECT the reference at all if it has also a status of 2 or any other status for that matter. status refers to the state of the transaction.
Current data table:
reference | amount | status
1 100 1
2 120 1
2 -120 2
3 200 1
3 -200 2
4 450 1
Result:
amount | status
550 1
I've simplified the data example but I think it gives a good idea of what I'm looking for.
I'm unsuccessful in selecting only references that only have status 1.
I've tried sub-queries, using the HAVING clause and other methods without success.
Thanks