Subject: Re: How to query by month?
To: taizi <taizi2006blog@163.com>, pgsql-admin@postgresql.org
References: <35257d1c.b253.158b06aaae5.Coremail.taizi2006blog@163.com>
From: "Joshua D. Drake" <jd@commandprompt.com>
Organization: Command Prompt, Inc.
Message-ID: <642f883e-7f57-bf82-6f36-753d0e0eeb0d@commandprompt.com>
Date: Tue, 29 Nov 2016 09:00:05 -0800
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101
 Thunderbird/45.4.0
MIME-Version: 1.0
In-Reply-To: <35257d1c.b253.158b06aaae5.Coremail.taizi2006blog@163.com>
Content-Type: text/plain; charset=gbk; format=flowed
Content-Transfer-Encoding: 7bit
Precedence: bulk
Sender: pgsql-admin-owner@postgresql.org

On 11/29/2016 06:08 AM, taizi wrote:
> Hi all,
> im a beginner for SQL, and  trying to use it with my daily work.
> Now i catched this question(my title of mail).
> Suppose there is a table about orders, i want to sum the total amount of
> each month.
> There was a statement of mine to november.
> select  sum(order_amount) FROM table_name WHERE order_date between
> '2016-11-01' AND '2016-11-30';
> I know it comes a result what i want, but i hope someone can tell me
> another way to use.
> After searched, i found  there is a function named date_part, but it
> doesn't work.

select sum(order_amount) from table_name where date_part('month', 
order_date) = '$month';

Note that the $month will be the month number, not name. So for 
November, it will = 11.

JD


> thanks for any help!
> Leopold
>
>
>
>
>


-- 
Command Prompt, Inc.                  http://the.postgres.company/
                         +1-503-667-4564
PostgreSQL Centered full stack support, consulting and development.
Everyone appreciates your honesty, until you are honest with them.
Unless otherwise stated, opinions are my own.


-- 
Sent via pgsql-admin mailing list (pgsql-admin@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-admin