From: Zac <zaccheob@inwind.it>
To: pgsql-sql@postgresql.org
Subject: Re: How to join several selects
Date: Wed, 24 Aug 2005 17:26:35 +0200
Message-ID: <dei3fi$2miq$1@news.hub.org> (raw)
In-Reply-To: <430C7A21.9020306@openwired.net>
References: <430C7A21.9020306@openwired.net>
Josep Sanmartí wrote:
> Hello,
> I have a 'big' problem:
> I have the following table users(name, start_time, end_time), a new row
> is set whenever a user logs into a server. I want to know how many
> users have logged in EVERYDAY between 2 different dates. The only idea
> that I have is making several select (one for each day):
> SELECT COUNT(name) FROM users WHERE start_time between "startDate"
> and "startDate+1"
> SELECT COUNT(name) FROM users WHERE start_time between "startDate+1"
> and "startDate+2"
> ...
> I would like to know if its possible to make it in 1 sql statement or
> just which is the best efficient way to solve it.
> By the way, I use Postgres 7.4.
>
> Thanks!
>
SELECT
date_trunc('day', start_time) as day, count(name)
FROM
users
WHERE
start_time between "startDate" AND "endDate"
GROUP BY
day;
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-sql@postgresql.org
Cc: zaccheob@inwind.it
Subject: Re: How to join several selects
In-Reply-To: <dei3fi$2miq$1@news.hub.org>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox