Message-ID: <7c4b1acc-951b-473f-bdc3-c4ae7298f875@rodonnell.ie>
Date: Sat, 18 May 2024 16:04:44 +0100
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Subject: Re: Left join syntax error
To: Rich Shepard <rshepard@appl-ecosys.com>,
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From: Ray O'Donnell <ray@rodonnell.ie>
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On 18/05/2024 16:01, Rich Shepard wrote:
> On Sat, 18 May 2024, Ray O'Donnell wrote:
>
>> You need to include the alias for the table also - see "...from 
>> companies as c..." in Shammat's example.
>
> Ray,
>
> That didn't work:
> bustrac-# FROM people as p, companies as c
> bustrac-# LEFT JOIN companies as c ON c.company_nbr = p.company_nbr;
> ERROR:  table name "c" specified more than once
>
> so I tried only the alias on the join line:
> bustrac-# LEFT JOIN c ON c.company_nbr = p.company_nbr;
> ERROR:  relation "c" does not exist
> LINE 3: LEFT JOIN c ON c.company_nbr = p.company_nbr;
>                   ^
> and that didn't work either.

Hi Rich,

Look again at Shammat's example! -

SELECT p.lname, p.fname, p.job_title, p.company_nbr, p.email, 
c.company_name
FROM people as p
   LEFT JOIN companies as c ON c.company_nbr = p.company_nbr

NB - "... from people as p left join companies as c on ...." - i.e. the 
companies table (or its alias c) is only specified once.

HTH,

Ray.


>
> Thanks,
>
> Rich
>
>


-- 
Raymond O'Donnell // Galway // Ireland
ray@rodonnell.ie