Octavian,
I need to extract a list which the following values from this table, for each hour (in date_time field):
- symbol - min(price) - max(price) - price where date_time is the earliest for that certain hour. - price where the date_time is the last from that hour. - The sum of volume from that hour.
Groupwise aggregates again. Very often required & asked about. See http://www.artfulsoftware.com/queries.php#18 and http://www.artfulsoftware.com/queries.php#19 for two typical answers.
PB Octavian Rasnita wrote:
Hi, I have a table with the following fields: symbol, date_time, price, volume I need to extract a list which the following values from this table, for each hour (in date_time field): - symbol - min(price) - max(price) - price where date_time is the earliest for that certain hour. - price where the date_time is the last from that hour. - The sum of volume from that hour. I have tried to get the list of symbols, then get each hourly period and calculate those 6 values for each period, but there are many symbols and very many periods, and it takes very very much time. Is there a more intelligent way of getting those values in another way than symbol by symbol and period by period? Thank you very much. Teddy
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