Thanks for the answer. The SQL does not need to be like that, my SQL 
knowledge is basic and that was the solution a colleague gave me. I want to 
get the posts with the tags in one query, but I couldn't figure a solution. 

I tested what you suggested but I see my knowledge of sqlalchemy is still 
not enough to solve this problem. I'll stick with the raw text solution 
right now.

Many thanks for the help.

El martes, 20 de noviembre de 2018, 1:25:13 (UTC-5), Mike Bayer escribió:
>
> On Mon, Nov 19, 2018 at 11:02 PM <[email protected] <javascript:>> 
> wrote: 
> > 
> > Hi everyone, 
> > 
> > I started with sqlalchemy a couple of weeks ago and I still have plenty 
> to learn. I'm trying to translate this query to the expression language, 
> but I have not been able to get what I need (right now I'm using text): 
>
> the ARRAY() call with a subquery inside of it is not really a standard 
> SQL syntax, it looks like you're trying to do a "nested select". 
> I've only known one proprietary database (Akiban, later FoundationDB) 
> that did that kind of query as a normal feature.   I would assume in 
> this case you're on Postgresql. 
>
> Anyway, if you *really* need the SQL to be like that,  you can use 
> sqlalchemy.dialects.postgresql.ARRAY with a scalar select inside of 
> it: 
>
> col = 
> postgresql.ARRAY(select([t.c.title]).select_from(...).where(...).as_scalar()) 
>
>
>
>
>
> > SELECT p.id, p.title, 
> > ( 
> > SELECT ARRAY(SELECT t.title 
> > FROM tags_posts pt 
> > JOIN tags t ON t.id=pt.tag 
> > WHERE pt.post = p.id) 
> > ) AS post_tags 
> > FROM posts p 
> > ORDER BY p.title; 
> > 
> > Thanks for any guidance. I've been stuck on this for a couple of days. 
> > 
> > -- 
> > SQLAlchemy - 
> > The Python SQL Toolkit and Object Relational Mapper 
> > 
> > http://www.sqlalchemy.org/ 
> > 
> > To post example code, please provide an MCVE: Minimal, Complete, and 
> Verifiable Example. See http://stackoverflow.com/help/mcve for a full 
> description. 
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-- 
SQLAlchemy - 
The Python SQL Toolkit and Object Relational Mapper

http://www.sqlalchemy.org/

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