Обсуждение: help formualting a query

I am having a hard time figuring out to do this, the SQL way. Doing in a
procedural way with a foreach would be deasy, but I suspect that a
properly formulated SQL query can achieve this.

I have a table that contains a  series of rows. Each row has a project key,
a start date, and an end date. There are multiple rows with different start
and end dates for each project.

I need to return something that contains, one row per project key, with the
min(star date) and max(end date) for ALL the records for that given
project.

Any suggestions?


--
"They that would give up essential liberty for temporary safety deserve
neither liberty nor safety."
                        -- Benjamin Franklin

stan <stanb@panix.com> writes:
> I have a table that contains a  series of rows. Each row has a project key,
> a start date, and an end date. There are multiple rows with different start
> and end dates for each project.

> I need to return something that contains, one row per project key, with the
> min(star date) and max(end date) for ALL the records for that given
> project.

Maybe I'm misunderstanding something, but isn't this just

select project_key, min(start_date), max(end_date)
from my_table
group by project_key

??

            regards, tom lane