[PATCH] Documentation: remove confusing paragraph about backslash escaping

On Mon, Feb 27, 2012 at 10:17 AM, Hannes Frederic Sowa <hsowa@bfk.de> wrote:

As with recent changes to `standard_conforming_strings' the paragraph about
backslash escaping in the description of `LIKE' is only confusing. Thus I
attached a patch to remove it.

I think I agree with removing this paragraph; it made sense when
standard_conforming_strings=off was the default, but that's not so
anymore. We could come up with some alternative text to insert here
but I think that might be unnecessarily long-winded.

Other opinions?

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company

Hannes Frederic Sowa <hsowa@bfk.de> writes:

As with recent changes to `standard_conforming_strings' the paragraph
about backslash escaping in the description of `LIKE' is only confusing.
Thus I attached a patch to remove it.

The para is still relevant if you don't have standard_conforming_strings
on. It could probably use work but I don't think simply removing it
is appropriate.

regards, tom lane

* Tom Lane:

Hannes Frederic Sowa <hsowa@bfk.de> writes:

As with recent changes to `standard_conforming_strings' the paragraph
about backslash escaping in the description of `LIKE' is only confusing.
Thus I attached a patch to remove it.

The para is still relevant if you don't have standard_conforming_strings
on.

And if you aren't using parametrized queries. The old text is a bit
misleading even with standard_conforming_strings set to off. It is
technically correct because it refers to the SQL statement parser which
is run on parameters, but this seems a pretty fine distinction.

--
Florian Weimer <fweimer@bfk.de>
BFK edv-consulting GmbH http://www.bfk.de/
Kriegsstraße 100 tel: +49-721-96201-1
D-76133 Karlsruhe fax: +49-721-96201-99

Robert Haas <robertmhaas@gmail.com> writes:

On Mon, Feb 27, 2012 at 10:17 AM, Hannes Frederic Sowa <hsowa@bfk.de> wrote:

As with recent changes to `standard_conforming_strings' the paragraph about
backslash escaping in the description of `LIKE' is only confusing. Thus I
attached a patch to remove it.

I think I agree with removing this paragraph; it made sense when
standard_conforming_strings=off was the default, but that's not so
anymore. We could come up with some alternative text to insert here
but I think that might be unnecessarily long-winded.

On a closer look, I see three different places in the
functions-matching.html page that talk about doubling backslashes, of
which this one might be the least bogus, since it at least provides
a cross-reference to someplace where you would read about
standard_conforming_strings.

I suggest replacing the first and third cases with something along the
lines of

Note: if you have standard_conforming_strings turned off, any
backslashes you write in literal string constants will need to be
doubled. See Section 4.1.2.1 for more information.

The second case is just a parenthetical comment and perhaps could be
removed.

regards, tom lane

On 02/28/2012 12:10 AM, Tom Lane wrote:

I suggest replacing the first and third cases with something along the
lines of

Note: if you have standard_conforming_strings turned off, any
backslashes you write in literal string constants will need to be
doubled. See Section 4.1.2.1 for more information.

The second case is just a parenthetical comment and perhaps could be
removed.

Definitely OK by me. Thanks for looking into this!

--
Hannes Sowa <hsowa@bfk.de>
BFK edv-consulting GmbH http://www.bfk.de/
Kriegsstra�e 100 tel: +49-721-96201-1
D-76133 Karlsruhe fax: +49-721-96201-99