[snip]Hi,
I have a problem I dont really know how to solve except for writing a function.
What I would like to calculate is:
a) the difference of the past 2 days for every security of available prices
Find the maximum date for a give SecCode (simple enough) and then the maximum date that is smaller than the one you just found (assuming no repetition of dates for a given SecCode).
b) a flag indicating, that the price of today-1 is yesterday's price (true in case A0001, false for A0002)
SELECT ... (PriceDate = (CURRENT_DATE - 1)) AS is_yesterday, ...
c) the variance of the past 30 days
Variance aggregate function
Is it possible to do that within one query?
Three sub-queries and some joining, certainly. It'll be a big query mind, perhaps worth wrapping in a function.
-- Richard Huxton Archonet Ltd
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