Just 1 in a series...
Mark Fenbers <Mark.Fenbers <at> noaa.gov>
2005-12-02 17:15:29 GMT
I currently have a working SQL that SELECTs all records whose
'river_stage' column exceeds the 'flood_stage' column. (Very simple --
no applause needed.) Typically, if I get one record, I get a
consecutive series of them since rivers rise and fall in a continuous
fashion, and usually respond lethargically when this much water is in
the rivers. This time-series of river stages all have (another column
called) 'event_id' set to the same integer value, so long as the river
has not fallen below flood stage (which will trigger the event_ID to be
However, I only want the first occurrence of a such a series (where the
event_id is the same), what SQL syntax should I use to do this?
I tried playing with different combinations using DISTINCT, GROUP BY,
and LIMIT 1, but I have had no success getting the results I'm looking
for, thus far. So I figured I might get farther faster by asking the
group. I must be misunderstanding the "GROUP BY" clause because I get
an error essentially stating that I need to list every column in the
SELECT list in the GROUP BY list (which makes it ineffective)...
My knots are tangled. Can someone please send advice regarding this issue?
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