bug with distinct?
I dont' know if this a bug or I am just out of my mind, but since it
works with other RDBMS's I decided to ask, so here it goes:
I am trying to do the following:
SELECT distinct 'mod_type' ,currval('mytable_idmytable_seq') from
mytable;
and I get the message:
ERROR: Unable to identify an ordering operator '<' for type 'unknown'
Use an explicit ordering operator or modify the query
Thinking it could be because of the currval I tried the following:
SELECT distinct 'mod_type', idmytable from mytable
getting the same result.
Am I doing something wrong? Is there a way to do this? Is this a bug?
Thanx
P.S. If someone is wondering what the heck I am trying to do.... I
pretend to insert into a log table, the mod_type for 'mytable' (in this
case insert) and the new inserted row for 'mytable'.
Cheers
Alfonso Peniche writes:
SELECT distinct 'mod_type' ,currval('mytable_idmytable_seq') from
mytable;and I get the message:
ERROR: Unable to identify an ordering operator '<' for type 'unknown'
Use an explicit ordering operator or modify the query
Use 'mod_type'::text.
--
Peter Eisentraut peter_e@gmx.net http://yi.org/peter-e/
Alfonso Peniche <alfonso@iteso.mx> writes:
SELECT distinct 'mod_type' ,currval('mytable_idmytable_seq') from
mytable;
ERROR: Unable to identify an ordering operator '<' for type 'unknown'
Use an explicit ordering operator or modify the query
You need to give the literal an explicit type, eg,
SELECT distinct 'mod_type'::text, currval('mytable_idmytable_seq') from
mytable;
7.1 will default to assuming that you meant 'text' in this scenario,
but older releases are pickier.
regards, tom lane
Quoting Tom Lane <tgl@sss.pgh.pa.us>:
Alfonso Peniche <alfonso@iteso.mx> writes:
SELECT distinct \'mod_type\'
,currval(\'mytable_idmytable_seq\') from
mytable;
ERROR: Unable to identify an ordering operator \'<\'
for type \'unknown\'
Use an explicit ordering operator or modify the
query
You need to give the literal an explicit type, eg,
SELECT distinct \'mod_type\'::text,
currval(\'mytable_idmytable_seq\')
from
mytable;7.1 will default to assuming that you meant \'text\' in
this scenario,
but older releases are pickier.
regards, tom lane
Thanx, it woeks great now.
Cheers
---