On Sun, 13 May 2007, Andrus wrote:
> I need to create function GOMONTH which returns date by given number of
> month before or forward using sql or pgsql in 8.1+ For example, GOMONTH(
> DATE '20070513', 1 ) should return date '20070613' GOMONTH( DATE
> '20070513', -2 ) should return date '20070313'
Andrus,
I do not know the context for which you need this, but you can use SQL to
calculate DATE + INTERVAL. For example, you could include in a SELECT
statement
WHERE CURRENT_DATE BETWEEN (DATE '20070513' - INTERVAL '2 month') AND
(DATE '20070513' + INTERVAL '1 month')
The PostgreSQL docs have an excellent section on temporal data types.
Also, search Google with the string 'Richard T. Snodgras' (at the University
of Arizona) and download the pdf copy of his book, 'Developing Time-Oriented
Database Applications in SQL.' I learned of this book just this morning.
HTH,
Rich
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