weird error message

From: Michael Moore <michaeljmoore(at)gmail(dot)com>
To: postgres list <pgsql-sql(at)postgresql(dot)org>
Subject: weird error message
Date: 2016-05-05 20:14:07
Message-ID: CACpWLjMK8J2O_zjrhBgfYoYU=eO=+CNO7DE0BNM6YNTkbYV4Hw@mail.gmail.com
Views: Whole Thread | Raw Message | Download mbox | Resend email
Thread:
Lists: pgsql-sql

SELECT COALESCE(dt, i) FROM (SELECT null AS dt, null AS i) q;
gives
ERROR: failed to find conversion function from unknown to text
********** Error **********

ERROR: failed to find conversion function from unknown to text
SQL state: XX000

So, I understand the datatype of 'null' is 'unknown', but what does 'text'
have to do with it?

Mike

Responses

Browse pgsql-sql by date

  From Date Subject
Next Message Adrian Klaver 2016-05-06 13:53:23 Re: weird error message
Previous Message David G. Johnston 2016-04-29 16:33:43 Re: Getting the queried result in the form of json structure