Re: [HACKERS] Undefined psql variables

I was giving some thought to how psql handles undefined variables.

I would like an option where either psql can provide an alternate value when an undefined variable is referenced, or a way to detect that a specific variable is undefined and replace it with a defined variable.

My first thought thought was to have a

 

\set_if_undefined var_name 'default_value'

Another idea adding a \pset parameter that would return a specific value when an undefined psql variable is referenced instead of raising an error. Like this:

# select :'x' as value_of_x;

ERROR:  syntax error at or near ":"

LINE 1: select :'x' as value_of_x;

               ^

# \pset variable_default ''

analytics=# select :'x' as value_of_x;

 value_of_x

------------

(1 row)