On 11/17/24 11:44, Achilleas Mantzios wrote:
Στις 16/11/24 18:09, ο/η Adrian Klaver έγραψε:
On 11/16/24 03:15, Achilleas Mantzios wrote:
Στις 16/11/24 12:55, ο/η Max Ulidtko έγραψε:
Greetings, group!
I'm trying to understand a low-level issue. Am evaluating a new
client library for Postgres; it's not particularly popular /
mainstream, and as I've understood so far, sports an independent
implementation of PG binary protocol.
The issue I'm hitting with it is exemplified by server logs like this:
2024-11-16 10:28:19.927 UTC [46] LOG: statement: SET client_encoding
= 'UTF8';SET client_min_messages TO WARNING;
2024-11-16 10:28:19.928 UTC [46] LOG: execute <unnamed>: CREATE VIEW
public.foobar (alg, hash) AS VALUES ('md5', $1);
At least for SQL level prepared statements the statement has to be
one of :
|SELECT|, |INSERT|, |UPDATE|, |DELETE|, |MERGE|, or |VALUES|
|so CREATE is not valid, and I guess the extended protocol prepared
statements aint no different in this regard.
It would seem so. Using psycopg:
import psycopg
from psycopg import sql
con =
psycopg.connect("postgresql://postgres:postgres@127.0.0.1:5432/test")
cur = con.cursor()
cur.execute("CREATE VIEW public.foobar (alg, hash) AS VALUES ('md5',
%s)", ['test'])
IndeterminateDatatype: could not determine data type of parameter $1
cur.execute(sql.SQL("CREATE VIEW public.foobar (alg, hash) AS VALUES
('md5', {})").format(sql.Literal('test')))
con.commit()
cur.execute("select * from foobar")
cur.fetchone()
('md5', 'test')
I dont know python but this does not look like a solid prepared statement.
https://www.psycopg.org/psycopg3/docs/advanced/prepare.html
Does not seem to have used the prepared statement circuitry.
The second example is not and was not meant to be. It was meant to show
how you could dynamically create an SQL statement when it will not
accept parameters.
FYI, this was run using psycopg(3) which does things differently, by
default, then psycopg2. For full explanation see:
https://www.psycopg.org/psycopg3/docs/basic/from_pg2.html
Server-side binding
--
Adrian Klaver
adrian.klaver@xxxxxxxxxxx
