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Message-ID: <387a4f5e-5886-443d-bc4e-e649706173a4@aklaver.com>
Date: Mon, 22 Apr 2024 09:50:31 -0700
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Subject: Re: Safe SELECT ... LIKE abc% in psycopg
To: Philippe Strauss <philippe@straussaudio.ch>, psycopg@lists.postgresql.org
References: <6b4e2581-8b08-4f0c-b159-cd078fd988a9@straussaudio.ch>
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From: Adrian Klaver <adrian.klaver@aklaver.com>
In-Reply-To: <6b4e2581-8b08-4f0c-b159-cd078fd988a9@straussaudio.ch>
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On 4/22/24 09:34, Philippe Strauss wrote:
> Hello, I'm Philippe from switzerland,
> 
> I'm writing using python a small JSON API for a mycology photos archive 
> webapp. Aside the main API endpoint are two
> helpers for an autocomplete form.
> Here is the first one:
> 
> --8<--
> @app.route('/genus/<genus>')
> def genus(genus):
>      with dbconn.cursor() as cur:
>          cur.execute("""SELECT myco.genus.name
>              FROM myco.genus
>              WHERE myco.genus.name LIKE %s""", (genus.upper()+'%',))
>          lsgenus = cur.fetchall()
>          ls = []
>          for genus in lsgenus:
>              ls.append(genus[0])
>      return jsonify(ls)
> --8<--
> 
> My questions:
> - What is the best way to use in psycopg3 to express a SELECT ... WHERE 
> ... LIKE blah% ?
> - Is my code above safe or vulnerable to a injection attack?
> - What peoples having passed on the same pattern have to recommend?

Read:

https://www.psycopg.org/psycopg3/docs/basic/params.html

It will answer the above.

For this case from link:

"When parameters are used, in order to include a literal % in the query 
you can use the %% string:"

> 
> Thanks!
> 

-- 
Adrian Klaver
adrian.klaver@aklaver.com