Обсуждение: Re: [pgadmin-support] Overloading functions that are used by operators.

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Re: [pgadmin-support] Overloading functions that are used by operators.

От
"Dave Page"
Дата:
Ahh, thanks. Was just looking at that.
 
Well I always thought you could overload functions in this way, however with your example below, although it creates it OK, PostgreSQL (not pgAdmin) gives the error 'ERROR: There is more than one function named textcat'.
 
As I said, I'm pretty sure that you can overload functions (in fact I know you can - there's one of mine in PostgreSQL 7.3!). I wonder if in this case the system knows that it can implicitly cast the arguments of one function to the other and hence the error is given?
 
Would this be the case for your citext datatype?
 
Regards, Dave.
-----Original Message-----
From: Donald Fraser [mailto:demolish@cwgsy.net]
Sent: 08 July 2003 21:27
To: Dave Page
Subject: Re: [pgadmin-support] Overloading functions that are used by operators.

Hi Dave,
if you want an easy way to reproduce it do the following:
 
CREATE FUNCTION pg_catalog.textcat(varchar, text) RETURNS text AS 'textcat' LANGUAGE 'internal' IMMUTABLE STRICT;
This wouldn't normally be necessary as we have type casting that will handle it and or operators but anyway that's beside the point...
 
Either the above statement is illegal or you have to find a different method for locating the function name associated with an operator.
That's the crux of the matter.
 
Regards
Donald Fraser.
----- Original Message -----
From: Dave Page
Sent: Tuesday, July 08, 2003 9:12 PM
Subject: RE: [pgadmin-support] Overloading functions that are used by operators.

 
-----Original Message-----
From: Donald Fraser [mailto:demolish@cwgsy.net]
Sent: 08 July 2003 21:00
To: [ADMIN]
Cc: [pgADMIN]
Subject: [pgadmin-support] Overloading functions that are used by operators.

I have a question regarding operators which are causing problems with the new pgAdmin III software being developed and my database.
The problem has been discussed in depth with the pgAdmin III development team and they have not been able to resolve the issue and suggested that I have either done something that I shouldn't have of or that there is a possible bug with postgresql. 
 
Where was it discussed in depth? The last I heard was that Andreas was going to look into it.
 
I will see if I can reproduce the problem myself.
 
Regards, Dave.

Re: [pgadmin-support] Overloading functions that are used by operators.

От
Tom Lane
Дата:
"Dave Page" <dpage@vale-housing.co.uk> writes:
> Well I always thought you could overload functions in this way, however
> with your example below, although it creates it OK, PostgreSQL (not
> pgAdmin) gives the error 'ERROR: There is more than one function named
> textcat'.

I see no such error here ...

regression=# create function pg_catalog.textcat(varchar,text)
regression-# returns text as 'textcat' language 'internal';
CREATE FUNCTION


            regards, tom lane