Re: help please

Dear all,

I have 3 column: date, time, stocks name, price

I have 2 questions:

1. what is the command (or query languange) to get the
the first and/or last observations for any given day (i know it can be done in
aggregate query, in Ms acces but can it be done in SQL server query as well?)?
e.g. I want to get the first and last price of the day for any particular stocks

2. how to calculate return with the following formula:
return=log P(t)-log P(t-1), where P(t) is price at
time t say 10 am and P(t-1) is price at one period
previous t say 9 am?

Regards

CharlyThe min and max functions will tell you the price ranges

eg select max(pricecolumn) from tablename where date='20040517'

select min(pricecolumn) from tablename where date='20040517'

If you want to be more selective look at the date/time setting you are using in your data and tailor the where command to select at that particular time

eg where date='2003-02-28 10:00:00.000'

Look at books online for the log function, and use selective where clauses for the times, ie where date='2004-05-17 10:00:00.000'|||select max(pricecolumn) from tablename where date='20040517'
broup by [stocks name]