Converting varchar to bool - Mailing list pgsql-sql

From KÖPFERL Robert
Subject Converting varchar to bool
Date
Msg-id ED4E30DD9C43D5118DFB00508BBBA76EB1676C@neptun.sonorys.at
Whole thread Raw
Responses Re: Converting varchar to bool  (Bruno Wolff III <bruno@wolff.to>)
List pgsql-sql
Hi, 


I have currently trouble working with boolean values and variables in
functions.

As one would expect, a
select '1'::bool, 't'::bool, 'true'::unknown::boolean

works.

As a select '1' tells us this seems as a conversion unknown->bool
or ??maybe?? a boolean literal??

what-o-ever, at least my function gets not accepted:


CREATE OR REPLACE FUNCTION testbool(varchar) RETURNS boolean AS
$BODY$
SELECT $1::boolean
$BODY$ LANGUAGE 'sql' STABLE STRICT SECURITY DEFINER;

Postgres complains that it can't convert varchar to boolean.
Actually neither  $1::unknown::bool works.
It turns out that there exists no conversion varchar/text/unknown ->
boolean.
Actually there's not any conversion  -> boolean.

How should this be treaten?
*being confused*


sorry for duplicating (I'm sure) this topic, at least I tried to find it in
the listarcive.


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