Aggregate functions
От | John Duffy |
---|---|
Тема | Aggregate functions |
Дата | |
Msg-id | 002801c08ee0$aab41140$75cc2cc3@desktop обсуждение исходный текст |
Ответы |
Re: Aggregate functions
|
Список | pgsql-general |
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
В списке pgsql-general по дате отправления: