It was hinted at in previous responses, but if you do:
Select * from t1;
and then again
select * from t1;
You have no guarantee that the results will be in the same order. So, even if your query DID work, it would be meaningless because you should consider the records to come in a random order. Never assume the order, always specify it if it is important.
On 03/23/2016 12:00 PM, Emi wrote: > Hello, > > For psql8.3, is there a simple way to query based on row number please? > > For example, > > select case > when row_num=1 THEN t1.tot_hr > ELSE t1.tot_hr - t1.pre_hr > END > FROM t1 ; > > > > > I seem to recall other posts from condordia: Someone needs to take of their skates and update postgres!
If this works, then wrap the query with a main query that uses "rownum" in the case statement.
STeve
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