Обсуждение: Select groupping by one column
Hello list, I have a table called pedh that looks like this: REFNO FECHA OCNUM PVD 0199 10/12/2003 5224 632 0199 10/12/2003 5224 632 1264 10/18/2003 8991 210 1264 10/18/2003 8991 210 1264 10/18/2003 8991 210 9093 10/20/2003 6895 520 9093 10/20/2003 6895 520 I need to select one record groupped by column refno, I tried using this code: select refno, max(fecha), max(ocnum), max(pvd) from pedh It seems to work fine, but is there another way to get the same result avoing use of aggregate functions? Thanks in advance -- Josué Maldonado
On Thu, Dec 18, 2003 at 15:09:52 -0800, Josué Maldonado <josue@lamundial.hn> wrote: > Hello list, > > I have a table called pedh that looks like this: > > REFNO FECHA OCNUM PVD > 0199 10/12/2003 5224 632 > 0199 10/12/2003 5224 632 > 1264 10/18/2003 8991 210 > 1264 10/18/2003 8991 210 > 1264 10/18/2003 8991 210 > 9093 10/20/2003 6895 520 > 9093 10/20/2003 6895 520 > > I need to select one record groupped by column refno, I tried using this > code: > > select refno, max(fecha), max(ocnum), max(pvd) from pedh I don't see how that could work. Maybe you left off group by. But if you did the aggreates could come from different rows, which might not be what you want. > > It seems to work fine, but is there another way to get the same result > avoing use of aggregate functions? You might be able to use distinct on instead of aggregates.
Hello Bruno, Bruno Wolff III wrote: >> >>select refno, max(fecha), max(ocnum), max(pvd) from pedh > > > I don't see how that could work. Maybe you left off group by. But if you > did the aggreates could come from different rows, which might not be what > you want. I missed the group by 1, I'm sorry. > > >>It seems to work fine, but is there another way to get the same result >>avoing use of aggregate functions? > > > You might be able to use distinct on instead of aggregates. Thanks