Re: Script generation through psql

On Tue, 2025-10-21 at 17:51 -0300, Mauricio Fernandez wrote:
> I'm trying to generate an script file as the output from psql script been called from linux bash, and I've two
issues:
>
> The bash call is like:
>
> psql -U myusr-d mydb -f ./scr.sql > $UPD_FILE 2>&1
>
> $ cat scr.sql
> \set vl_id 19
> \set ECHO none
> \pset tuples_only on
> \pset pager off
>
> select script_drop from proceso_actualiza_fdw where id = :vl_id;
>
> select script_import from proceso_actualiza_fdw where id = :vl_id;
>
> \q
>
> 1.- The output file is like :
> Pager usage is off.
>  --                                                                  +
>  -- BORRADO DE TABLAS MODIFICADAS                                    +
>
> How can I eliminate "Pager usage is off." and the "+"  at the end of each row?

Rather than disabling the pager with a \pset command, set the PAGER environment
variable to an empty string before calling "psql".

To get rid of the "+" at the end of the line, use unaligned output.
I use the options -A, -t and -q when calling "psql" from a shell script.

So your shell script could look like

  PAGER=''
  psql -Atq -U ... -d ... -f ...

> 2. If in the psql script I want to pass variable values from an anonymous block to the rest of the script, how can I
proceed?.For example 
>
> DO $$
> DECLARE
>   vl_id integer;
> BEGIN
>  -- vl_id is set inside the procedure
>   call my_procedure(vl_id);
> END $$;
>
> select script_drop from proceso_actualiza_fdw where id = :vl_id;
>
> select script_import from proceso_actualiza_fdw where id = :vl_id;
>
> The script output file is the result set from the queries.
>
> I've tried with \set myvar but this doesn't works

You cannot grab any output from a DO statement.  I recommend that you don't use it.

Try something like the following in your "psql" script:

  -- without a DO statement
  CALL my_procedure(NULL) \gset

That will define a variable that has the same name as the parameter of the procedure
and set its value to the return value of the procedure.

Yours,
Laurenz Albe