Re: [HACKERS] Re: [GENERAL] Re: [PHP3] Re: PostgreSQL vs Mysql comparison

> Bruce Momjian <maillist(at)candle(dot)pha(dot)pa(dot)us> writes:
> > *** src/backend/parser/scan.l 1999/09/28 03:41:36 1.57
> > --- src/backend/parser/scan.l 1999/10/08 04:58:23
> > ***************
> > *** 167,173 ****
> >
> > param \${integer}
> >
> > ! comment ("--"|"//").*\n
> >
> > space [ \t\n\f]
> > other .
> > --- 167,173 ----
> >
> > param \${integer}
> >
> > ! comment ("--"|"//").*
> >
> > space [ \t\n\f]
> > other .
>
> Ah, so the problem was that the perl interface didn't append a newline?
> Good catch. I don't like this fix, however, since I fear it will
> alter behavior for the case where there is an embedded newline in the
> query buffer. For example
> CREATE TABLE mytab -- comment \n (f1 int)

No problem. I just added test code to see if it works, and it does:

$result = $conn->exec(
"CREATE TABLE person (id int4, -- test\n name char(16)) -- test");

Tests embedded newline, and comment without newline.

I will commit this so it will always be tested by the perl test code.

> can be sent to the backend as one string (though not via psql). With
> the above change in scan.l I think the comment will be taken to include
> everything from -- to the end of the buffer, which is wrong.

No, seems lex only goes the end-of-line unless you specifically say \n.

>
> A better solution IMHO is to leave scan.l as it was and instead
> always append a \n to the presented query string before we parse.

Problem here is that perl is not the only interface that would have this
problem. In fact, I am not sure why libpq doesn't have this problem.
Maybe it does. Anyway, changing all the interfaces would be a pain, and
non-portable to older releases.

>
> BTW, might be a good idea to add \r to that list of "space" characters
> so we don't mess up on DOS-style newlines (\r\n).

Interesting idea. I tried that, but the problem is things like this:

xqliteral [\\](.|\n)

If I change it to:

xqliteral [\\](.|\n|\r)

then \r\n is not going to work, and if I change it to:

xqliteral [\\](.|\n|\r)+

Then \n\n is going to be accepted when it shouldn't. Seems I will have
to leave it alone for now.

--
Bruce Momjian | http://www.op.net/~candle
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