Re: Getting return value from .callproc

On 06/27/2016 09:58 PM, Larry Sevilla wrote:

psql postgres
gives err:
psql; FATAL: role "root" does not exist.  (as root)
psql; FATAL: role "user" does not exist. (as user)

If you do not specify the -U switch(user) for psql it will use the system user that you are logged in as. If that user does not have a Postgres role then you get the above. To avoid the above and get the behavior you are getting with sudo, do the following as any system user:

psql -U postgres -d postgres

See:
https://www.postgresql.org/docs/9.4/static/app-psql.html

Usage
Connecting to a Database

By the way the -d postgres means you are connecting to one of the Postgres 'system' databases. That is not really where you want to create objects. I would suggest creating you own database in the cluster for doing your work.

https://www.postgresql.org/docs/9.4/static/sql-createdatabase.html

    >
    >
    > But if I use Python with psycopg2
    > -----
    > import psycopg2
    >
    > conn=psycopg2.connect(host='localhost',database='postgres',user='postgres',password='postgres')
    > cur=conn.cursor()
    >
    > retval = cur.callproc('personnelinsert',[34567,'Galilei, Galileo'])
    >
    > conn.commit()
    >
    > cur.close()
    > conn.close()
    >
    > print(retval)
    > -----
    > retval = [34567,'Galilei, Galileo']
    > (I'm expecting retval/serialid value of 3, not the parameters I sent)
    >
    >
    > Q1: From Python, is there a way I can retrieve the value of
    > "retval/serialid" of my UDF?

    Return values from Postgres functions are just like other expression
    values. The most straightforward way to retrieve your function's return
    value would be something like this:

    cur.execute('select personnelinsert(%s, %s)',[34567,'Galilei, Galileo'])
    retval = cur.fetchone()[0]

This is what I do also.


--
Adrian Klaver
adrian.klaver@aklaver.com