3
votes
0answers
138 views

Is there a First() aggregate function in postgresql that returns the exact same type as the input?

Full question re-write I'm looking a First() aggregate function. Here I found something that almost works: CREATE OR REPLACE FUNCTION public.first_agg ( anyelement, anyelement ) RETURNS anyelement ...
0
votes
1answer
54 views

How to add up a column depending on data from another column

I have a table which has results and a table that has band_name and band_id. Now I need to create a query which will add up the total points for each band and display the band name and ID, so far I ...
4
votes
1answer
414 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
2k 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 -- ...