4
votes
1answer
204 views

Is it possible to wrap aggregate functions in Postgres?

Postgres' string_agg(expr, delimiter) function is great. But I would like to have a version that takes a single argument -- the field to aggregate -- and assumes a delimiter of ', ' since that is ...
1
vote
2answers
472 views

How do I create a user-defined aggregate function?

I need an aggregate function that MySQL doesn't provide. I would like it to be in MySQL's flavor of SQL (that is, not in C). How do I do this? What I'm stuck on is creating an aggregate function -- ...