I really don't know how to ask for what I'm looking for; but I think, may be, calling it an ARRAY yielding aggregate function for use within a query WINDOW would do?
I'm looking for something like:
SELECT DISTINCT issuer,amount, array(REFERENCE) over (partition by invoice_nr) from invoices;
where the invoices table contain the usual invoice data, like: - amount - time of issue - the issuer ID - and the above REFERENCE, is the reference to a bank transfer record in another table.
The thing is, that I have multiple funds transfer records referring to a single invoice; and (I currently think, that :) I need to fetch them all in a single column - so preferrably within an ARRAY of references (or just transfer IDs) to table containing funds transfer records. In other words, I wouldn't like to collapse the query at the application level ... but "if everything else fails", that is the last resort I keep in mind.
The reason I'm not taking the last resort now, is that I also have multiple invoices to a single funds transfer record. And ultimately I'm hoping to cook a query, that would window-and-balance the two tables (invoices, and funds transfer) - so that most of the job is done by SQL/funciton/view, not by the external application.
I've looked up postgres documentation, looking for a sort of "aggregate" function, that would not compute anything, but just build an ARRAY from all its input, but couldn't locate any.
