Hi.
I have a simple table in which I store equity prices:
table prices (
equity_id integer,
date date,
price money);
I am happy with the following select statement:
SELECT equity_id, min(price), max(price)
FROM prices
WHERE date >= start_date AND date <= end_date
GROUP BY equity_id;
which produces a nice table of min and max prices for each equity between
two dates.
What I would like to be able to do is a select like this:
SELECT equity_id, start_date(price), end_date(price), min(price),
max(price)
...
Are there aggregate function, such as 'first' and 'last', that will store
the first and last row value of a series of rows ?
I have read the Extending Aggregates section of the Programmers Guide but it
is a bit beyond me. Any assistance in writing functions to do the above
would be appreciated.
Regards
John Duffy
jbduffy@cwcom.net
