Re: [help-recutils] recsel --join with multiple fields

[Héctor A . Abreu]

On Tue, Jul 10, 2018 at 01:03:34PM +0200, Jose E. Marchesi wrote:
> 
> Hi Héctor.
>     
>     Is it possible to include multiple fields in the recsel --join option
>     ? If not, that's fine, I guess I will figure it out how to solve my
>     recsel needs with this limitation. I can't remember if join by
>     multiple fields/columns is a common practice in SQL and I didn't find
>     any example of that kind in recutils documentation.
>     
>     Thank you in advance for any info or orientation.
>     
> --join accepts only one field, which should be defined as a foreign key
> in the referring record descriptor.  Something like:
> 
> %type: Abode rec Residence
> 
> This will make Abode a foreign key referring Residence's primary key.
> Since primary keys are limited to single fields in recutils, it follows
> that foreign keys should also be restricted to a single field and
> therefore joins are likewise limited.
> 
> What are you intending to do anyway?

Thank you for your reply!

I can't remember the specific query that I was trying to solve back in May when 
I posted this question for the first time, but I have managed to solve my query 
needs so far by using single fields in my recutils primary keys, as you said. 

What I've been doing for the last couple of months is to put together a 
database for my small online school's CRM. Since it's a small business and most 
of my admin tasks are run via ssh using CLI apps, I thought it could make sense 
to use recutils with well structured recfiles and bash scripts, and wait until 
the volume and complexity of the database activities will demand to migrate to 
MySQL. I estimate that I will be handling the records of hundreds students 
(actually leads + active students, since it's a CRM) for the first 6 to 10 
months. The busiest scenario I can picture is 2000 people in my database in 12 
months.

Do you think it makes sense to start my small CRM using recutils, and then 
migrate somehow to MySQL when volume and complexity will demand it? Or should I 
keep recutils for my personal databases (Org-mode stuff, for example), not even 
trying a CRM but rather using MySQL from the beginning for such a project?

Thank you in advance for your advise.
-- 
Héctor A. Abreu