On Mon, Jan 26, 2015 at 2:38 PM, Tim Smith <randomdev4+postgres@xxxxxxxxx> wrote:
create table templates(
template_id int not null primary key,
template_groupid int not null,
template_version int not null
template_text text not null);
Would I need to resort to using a CTE or subquery to make this sort of
thing work ? I can't seem to make it work with group by since group
by expects aggregation. Surely I don't need to normalise it into a
couple of tables ?
What sort of thing? Selecting the latest version of each template? Try
SELECT
DISTINCT ON (template_group_id) template_id, template_group_id, template_version, template_text
SELECT
DISTINCT ON (template_group_id) template_id, template_group_id, template_version, template_text
FROM
templates
ORDER BY
template_group_id, template_version DESC
You could even create a latest_templates view for this. DISTINCT ON is my favorite lesser-known Postgres feature.
You could even create a latest_templates view for this. DISTINCT ON is my favorite lesser-known Postgres feature.
