Thread: Check psql parameter is passed, if not ask for it

Check psql parameter is passed, if not ask for it

From
Wiwwo Staff
Date:
Hi!
I want to check if I pass the parameter "param1" to a sql script "delme.sql" like
```
\if ':param1'
  \echo :param1;
\else
  \prompt 'Param1? ' :param1
\endif
select :'param1';
```
if parameter `param1` is not passed, the .sql should ask for it.

If I run something like
`psql -f delme.sql -v param1=1`
it works, but if i pass
`psql -f delme.sql -v param1=meh`
i receive
`psql:delme.sql:1: error: unrecognized value ":param1" for "\if expression": Boolean expected`

How can I implement that?
TIA, Wiwwo

Re: Check psql parameter is passed, if not ask for it

From
Torsten Förtsch
Date:
to quote the documentation:

> If an unquoted colon (:) followed by a psql variable name appears within an argument, it is replaced by the variable's value, as described in SQL Interpolation below.
> The forms :'variable_name' and :"variable_name" described there work as well. The :{?variable_name} syntax allows testing whether a variable is defined. It is
> substituted by TRUE or FALSE. Escaping the colon with a backslash protects it from substitution.


On Mon, Aug 5, 2024 at 8:46 PM Wiwwo Staff <wiwwo@wiwwo.com> wrote:
Hi!
I want to check if I pass the parameter "param1" to a sql script "delme.sql" like
```
\if ':param1'
  \echo :param1;
\else
  \prompt 'Param1? ' :param1
\endif
select :'param1';
```
if parameter `param1` is not passed, the .sql should ask for it.

If I run something like
`psql -f delme.sql -v param1=1`
it works, but if i pass
`psql -f delme.sql -v param1=meh`
i receive
`psql:delme.sql:1: error: unrecognized value ":param1" for "\if expression": Boolean expected`

How can I implement that?
TIA, Wiwwo