Davor J. wrote:
Let's say you have a table:
CREATE TABLE t (
time date,
data integer
)
Suppose you want a new table that has columns similar to the following:
"(x.time, x.data, y.time, y.data, z.time, z.data)" where x.time, y.time and
z.time columns are constrained (for example x.time >2007 AND x.time <2008,
y.time >2008 AND y.time < 2009, z.time > 2010)
How would you do this. Note that you can not use JOIN as there is no
relationship.
Currently I came up with something like this:
SELECT X.*, (SELECT Y.time, Y.data FROM t AS Y WHERE Y.time = X.time + 1),
(SELECT Z.time .) FROM t AS X WHERE X.time >2007 AND X.time <2008
Um, why can't you use a join?
SELECT X.*, Y.time, Y.data FROM t AS X JOIN t as Y ON (Y.time = X.time + '1 year'::INTERVAL)
WHERE X.time >= '2007-01-01'::DATE AND X.time < '2008-01-01'::DATE;
I believe should be functionally equivalent to your nested select. I'm
not real sure what you're trying to imply with your date > integer
comparisions, so I tried to be a little more rigorous there.
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