Обсуждение: Re: ERROR: operator does not exist: integer !=- integer

On 2007-03-04, William ZHANG <uniware@zedware.org> wrote:
> Here is the steps to reproduce it in CVS HEAD:
> backend> select -1 !=-1;

This arguably isn't a bug, because != is not a standard SQL operator, and
therefore !=- can legitimately be defined as a single operator by the user.

-- 
Andrew, Supernews
http://www.supernews.com - individual and corporate NNTP services

Andrew - Supernews wrote:
> On 2007-03-04, William ZHANG <uniware@zedware.org> wrote:
>> Here is the steps to reproduce it in CVS HEAD:
>> backend> select -1 !=-1;
> 
> This arguably isn't a bug, because != is not a standard SQL operator, and
> therefore !=- can legitimately be defined as a single operator by the user.
> 

I missed the first post and can't seem to search for it - so correct me 
if I am missing something.

Isn't the problem here a missing space? != is a valid operator and -1 is 
the value you are comparing to. !=-1 is not valid but != -1 is correct 
and what I assume you are looking to achieve.

The negation operator goes with the int being negated and is not part of 
the comparison operator != the space is needed there to separate the two.



-- 

Shane Ambler
pgSQL@Sheeky.Biz

Get Sheeky @ http://Sheeky.Biz

>
> I missed the first post and can't seem to search for it - so correct 
> me if I am missing something.
>
> Isn't the problem here a missing space? != is a valid operator and -1 
> is the value you are comparing to. !=-1 is not valid but != -1 is 
> correct and what I assume you are looking to achieve.
>

Well yes it will work if you add a space, but technically the problem is 
the query should be written like this:

1 <>-1 or 1 <> -1

Joshua D. Drake



> The negation operator goes with the int being negated and is not part 
> of the comparison operator != the space is needed there to separate 
> the two.
>
>
>

I get it. scan.l converts '!=' to '<>':
   644                     /* Convert "!=" operator to "<>" for 
compatibility */   645                     if (strcmp(yytext, "!=") == 0)   646                         yylval.str =
pstrdup("<>");  647                     else   648                         yylval.str = pstrdup(yytext);
 


""Joshua D. Drake"" <jd@commandprompt.com>
>
> Well yes it will work if you add a space, but technically the problem is 
> the query should be written like this:
>
> 1 <>-1 or 1 <> -1
>
> Joshua D. Drake