Thread

1. BUG #18689: psql : operator "!=" do not behave like "<>"

   PG Bug reporting form <noreply@postgresql.org> — 2024-11-05T11:23:57Z

   The following bug has been logged on the website:
   
   Bug reference:      18689
   Logged by:          Joël HECHT
   Email address:      jhecht@cirilgroup.com
   PostgreSQL version: 15.6
   Operating system:   CentOS Linux release 7.9
   Description:        
   
   Hello,
   
   according to the documentation, operators != and <> are supposed to be
   interchangeable.
   But when operator "!=" is followed by a negative number, the request failed
   with an error "No operator matches the given name".
   
   Here is how to reproduce the issue directly with psql :
   
   
   [postgres@d04f96727d36 ~]$ psql
   psql (15.6)
   Type "help" for help.
   
   postgres=# select -1<>-1;
    ?column?
   ----------
    f
   (1 row)
   
   postgres=# select -1!=-1;
   ERROR:  operator does not exist: integer !=- integer
   LINE 1: select -1!=-1;
                    ^
   HINT:  No operator matches the given name and argument types. You might need
   to add explicit type casts.
   postgres=#
   
   
   Regards.
   
   

2. Re: BUG #18689: psql : operator "!=" do not behave like "<>"

   Rafia Sabih <rafia.pghackers@gmail.com> — 2024-11-05T13:02:36Z

   Thank you for reporting this. However I found that the lack of space in the
   statement is causing this.
   On trying it like select -1 != -1; it works fine.
   
   On Tue, 5 Nov 2024 at 13:39, PG Bug reporting form <noreply@postgresql.org>
   wrote:
   
   > The following bug has been logged on the website:
   >
   > Bug reference:      18689
   > Logged by:          Joël HECHT
   > Email address:      jhecht@cirilgroup.com
   > PostgreSQL version: 15.6
   > Operating system:   CentOS Linux release 7.9
   > Description:
   >
   > Hello,
   >
   > according to the documentation, operators != and <> are supposed to be
   > interchangeable.
   > But when operator "!=" is followed by a negative number, the request failed
   > with an error "No operator matches the given name".
   >
   > Here is how to reproduce the issue directly with psql :
   >
   >
   > [postgres@d04f96727d36 ~]$ psql
   > psql (15.6)
   > Type "help" for help.
   >
   > postgres=# select -1<>-1;
   >  ?column?
   > ----------
   >  f
   > (1 row)
   >
   > postgres=# select -1!=-1;
   > ERROR:  operator does not exist: integer !=- integer
   > LINE 1: select -1!=-1;
   >                  ^
   > HINT:  No operator matches the given name and argument types. You might
   > need
   > to add explicit type casts.
   > postgres=#
   >
   >
   > Regards.
   >
   >
   
   -- 
   Regards,
   Rafia Sabih
   CYBERTEC PostgreSQL International GmbH
   

3. Re: BUG #18689: psql : operator "!=" do not behave like "<>"

   Tom Lane <tgl@sss.pgh.pa.us> — 2024-11-05T14:56:22Z

   Rafia Sabih <rafia.pghackers@gmail.com> writes:
   > Thank you for reporting this. However I found that the lack of space in the
   > statement is causing this.
   > On trying it like select -1 != -1; it works fine.
   
   Right, see
   
   https://www.postgresql.org/docs/current/sql-syntax-lexical.html#SQL-SYNTAX-OPERATORS
   
   particularly the bit about "A multiple-character operator name cannot
   end in + or -, unless ...".  "!=-" will be treated as one operator,
   but "<>-" will not.
   
   			regards, tom lane
   
   
   
   

4. Re: BUG #18689: psql : operator "!=" do not behave like "<>"

   Erik Wienhold <ewie@ewie.name> — 2024-11-05T15:05:05Z

   On 2024-11-05 14:02 +0100, Rafia Sabih wrote:
   > Thank you for reporting this. However I found that the lack of space in the
   > statement is causing this.
   > On trying it like select -1 != -1; it works fine.
   
   The docs explain it in a bit more detail:
   https://www.postgresql.org/docs/current/sql-syntax-lexical.html#SQL-SYNTAX-OPERATORS
   
   "<>" is the standard inequality operator, whereas the operator name "!="
   is just an alias implemented by Postgres (and some other RDBMS).  That
   alias is subject to the same restrictions as outlined in the linked
   docs, i.e., Postgres parses the longer operator name "!=-" because it
   contains "!".
   
   > On Tue, 5 Nov 2024 at 13:39, PG Bug reporting form <noreply@postgresql.org>
   > wrote:
   > 
   > > The following bug has been logged on the website:
   > >
   > > Bug reference:      18689
   > > Logged by:          Joël HECHT
   > > Email address:      jhecht@cirilgroup.com
   > > PostgreSQL version: 15.6
   > > Operating system:   CentOS Linux release 7.9
   > > Description:
   > >
   > > Hello,
   > >
   > > according to the documentation, operators != and <> are supposed to be
   > > interchangeable.
   > > But when operator "!=" is followed by a negative number, the request failed
   > > with an error "No operator matches the given name".
   > >
   > > Here is how to reproduce the issue directly with psql :
   > >
   > >
   > > [postgres@d04f96727d36 ~]$ psql
   > > psql (15.6)
   > > Type "help" for help.
   > >
   > > postgres=# select -1<>-1;
   > >  ?column?
   > > ----------
   > >  f
   > > (1 row)
   > >
   > > postgres=# select -1!=-1;
   > > ERROR:  operator does not exist: integer !=- integer
   > > LINE 1: select -1!=-1;
   > >                  ^
   > > HINT:  No operator matches the given name and argument types. You might
   > > need
   > > to add explicit type casts.
   > > postgres=#
   
   -- 
   Erik