On 12/31/2012 8:33 AM, Robert James wrote:
I have a query SELECT grouping_field, MIN(field_a), MIN(field_b) FROM ... GROUP BY grouping_field But, instead of picking the MIN field_a and MIN field_b, I'd like to pick field_a and field_b from the first record, according to an order I'll specify. In pseudo-SQL, it would be something like this: SELECT grouping_field, FIRST(field_a), FIRST(field_b) FROM ... ORDER BY field_c DESC, field_d ASC, myfunc(field_e) ASC GROUP BY grouping_field How can I do that with Postgres?
select distinct on (grouping_field), field_a, field_b from ... order by grouping_field, field_a asc, field_b asc http://www.postgresql.org/docs/9.2/static/sql-select.html#SQL-DISTINCT -- Jack Christensen http://jackchristensen.com/ -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
