Quoting "

Andy Anderson wrote:

In a test I just did, the sequence \" (backslash double-quote) is
interpreted as just a " inside of the E'...' string constant expression.
This is great, since PHP's addslashes() sticks them in along with the
other stuff I really need to quote like ' and \. But I see that \" isn't
documented in the manual in section 4.1.2.1. I assume this is, in fact,
standard behavior for Postgres? (Perhaps a comprehensive table might be
a good idea at this point in the manual.)

craig=# SELECT E'\z\v\k\-';
?column?
----------
zvk-
(1 row)

From 4.1.2.1:

... "Any other character following a backslash is taken literally."

I didn't see any escape sequences being interpreted other than those
that're already documented in the section of 4.1.2.1 that describes E''
strings.

--
Craig Ringer

Andy Anderson <aanderson@amherst.edu> writes:

In a test I just did, the sequence \" (backslash double-quote) is
interpreted as just a " inside of the E'...' string constant
expression. This is great, since PHP's addslashes() sticks them in
along with the other stuff I really need to quote like ' and \. But I
see that \" isn't documented in the manual in section 4.1.2.1.

Huh? It says

Any other character following a backslash is taken literally.

regards, tom lane

Ah, slight ambiguity here. Perhaps this might best say "Any other
character following a backslash is taken literally, and the backslash
is removed."

Thanks,

-- Andy

On Apr 30, 2008, at 10:28 AM, Tom Lane wrote:

On Wed, Apr 30, 2008 at 7:10 AM, Andy Anderson <aanderson@amherst.edu> wrote:

In a test I just did, the sequence \" (backslash double-quote) is
interpreted as just a " inside of the E'...' string constant expression.
This is great, since PHP's addslashes() sticks them in along with the other
stuff I really need to quote like ' and \. But I see that \" isn't
documented in the manual in section 4.1.2.1. I assume this is, in fact,
standard behavior for Postgres? (Perhaps a comprehensive table might be a
good idea at this point in the manual.)

Why are you using php's addslashes() function? Is there something
missing from pg_escape_string()??? Or are you doing something else
I'm not thinking of?

On Wed, Apr 30, 2008 at 9:10 AM, Andy Anderson
<aanderson@amherst.edu> wrote:

In a test I just did, the sequence \" (backslash double-quote) is
interpreted as just a " inside of the E'...' string constant
expression.
This is great, since PHP's addslashes() sticks them in along with
the other
stuff I really need to quote like ' and \.

On Apr 30, 2008, at 11:52 AM, Scott Marlowe wrote:

Why are you using php's addslashes() function? Is there something
missing from pg_escape_string()??? Or are you doing something else
I'm not thinking of?

Yep, relying on what I already know to move forward on my project,
rather than browsing the manual for things I didn't know I needed :-).

Thanks for the tip.

-- Andy

On the list pgsql-general, I had this exchange:

Andy Anderson <aanderson@amherst.edu> writes:

In a test I just did, the sequence \" (backslash double-quote) is
interpreted as just a " inside of the E'...' string constant
expression. This is great, since PHP's addslashes() sticks them
in along with the other stuff I really need to quote like ' and
\. But I see that \" isn't documented in the manual in section
4.1.2.1. I assume this is, in fact, standard behavior for
Postgres? (Perhaps a comprehensive table might be a good idea at
this point in the manual.)

Tom Lane wrote:

Huh? It says

Any other character following a backslash is taken literally.

Andy Anderson wrote:

Ah, slight ambiguity here. Perhaps this might best say "Any other
character following a backslash is taken literally, and the
backslash is removed."

In any case, here's a contribution to the manual, a short table with
this information, in a format that might help make the subject
clearer. Modify at will!

-- Andy

<!--<TABLE BORDER="1" CLASS="CALSTABLE"> <COL><COL><COL> <THEAD> <TR>
<TH>Backslash Escape Sequence</TH> <TH>Interpretation</TH> <TH>Notes</
TH> </TR> </THEAD> <TBODY> <TR> <TD><TT CLASS="TOKEN">\b</TT></TD>
<TD>backspace</TD> <TD></TD> </TR> <TR> <TD><TT CLASS="TOKEN">\f</TT></
TD> <TD>form feed</TD> <TD></TD> </TR> <TR> <TD><TT CLASS="TOKEN">\n</
TT></TD> <TD>newline</TD> <TD></TD> </TR> <TR> <TD><TT CLASS="TOKEN">
\r</TT></TD> <TD>carriage return</TD> <TD></TD> </TR> <TR> <TD><TT
CLASS="TOKEN">\t</TT></TD> <TD>tab</TD> <TD></TD> </TR> <TR> <TD> <TT
CLASS="TOKEN">\<var>o</var></TT><br> <TT CLASS="TOKEN">\<var>oo</var></
TT><br> <TT CLASS="TOKEN">\<var>ooo</var></TT><br> </TD> <TD> octal
byte value </TD> <TD> <var>o</var> = 0 - 7 </TD> </TR> <TR> <TD> <TT
CLASS="TOKEN">\x<var>h</var></TT><br> <TT CLASS="TOKEN">\x<var>hh</
var></TT><br> </TD> <TD> hexadecimal byte value </TD> <TD> <var>h</
var> = 0 - F </TD> </TR> <TR> <TD><TT CLASS="TOKEN">\</TT><var>a</
var></TD> <TD><var>a</var></TD> <TD><var>a</var> = any other
character. Commonly used to include \ and '</TD> </TR> </TBODY> </
TABLE>-->

Andy Anderson wrote:

In any case, here's a contribution to the manual, a short table with
this information, in a format that might help make the subject clearer.
Modify at will!

FWIW if you really want to make a contribution to the docs, please see
the SGML sources instead of the HTML output (which is machine-generated).

http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/

--
Alvaro Herrera http://www.CommandPrompt.com/
PostgreSQL Replication, Consulting, Custom Development, 24x7 support

Andy Anderson wrote:

In any case, here's a contribution to the manual, a short table with
this information, in a format that might help make the subject
clearer.

Modify at will!

On Apr 30, 2008, at 6:04 PM, Alvaro Herrera wrote:

FWIW if you really want to make a contribution to the docs, please
see
the SGML sources instead of the HTML output (which is machine-
generated).

OK, then, I hope the following is accurate enough SGML to be more
useful. Submitted here per the instructions on <http://www.postgresql.org/docs/8.3/interactive/bug-reporting.html

.

-- Andy

********************************************************************

<table id="sql-backslash-table">
<title>Backslash Escape Sequences</title>
<tgroup cols="2">
<thead>
<row>
<entry>Backslash Escape Sequence</>
<entry>Interpretation</entry>
</row>
</thead>
<tbody>
<row>
<entry><literal>\b</literal></entry>
<entry>backspace</entry>
</row>
<row>
<entry><literal>\f</literal></entry>
<entry>form feed</entry>
</row>
<row>
<entry><literal>\n</literal></entry>
<entry>newline</entry>
</row>
<row>
<entry><literal>\r</literal></entry>
<entry>carriage return</entry>
</row>
<row>
<entry><literal>\t</literal></entry>
<entry>tab</entry>
</row>
<row>
<entry>
<literallayout>
<literal>\<replaceable>o</replaceable></literal>
<literal>\<replaceable>oo</replaceable></literal>
<literal>\<replaceable>ooo</replaceable></literal>
(<replaceable>o</replaceable> = 0 - 7)
</literallayout>
</entry>
<entry>octal byte value</entry>
</row>
<row>
<entry>
<literallayout>
<literal>\x<replaceable>h</replaceable></literal>
<literal>\x<replaceable>hh</replaceable></literal>
(<replaceable>h</replaceable> = 0 - F)
</literallayout>
</entry>
<entry>hexadecimal byte value</entry>
</row>
<row>
<entry>
<literallayout>
<literal>\<replaceable>a</replaceable></literal>
(<replaceable>a</replaceable> = any other character than the
above,
e.g. <literal>\</literal> and <literal>'</literal>.)
</literallayout>
</entry>
<entry><replaceable>a</replaceable></entry>
</row>
</tbody>
</tgroup>
</table>

Andy Anderson wrote:

Andy Anderson wrote:

In any case, here's a contribution to the manual, a short table with
this information, in a format that might help make the subject
clearer.

Modify at will!

On Apr 30, 2008, at 6:04 PM, Alvaro Herrera wrote:

FWIW if you really want to make a contribution to the docs, please
see
the SGML sources instead of the HTML output (which is machine-
generated).

OK, then, I hope the following is accurate enough SGML to be more
useful. Submitted here per the instructions on <http://www.postgresql.org/docs/8.3/interactive/bug-reporting.html

Good idea --- a table is certainly clearer. I modified your patch and
applied the attached version. Thanks much.

Your documentation changes can be viewed in five minutes at:

http://developer.postgresql.org/pgdocs/postgres/index.html

--
Bruce Momjian <bruce@momjian.us> http://momjian.us
EnterpriseDB http://enterprisedb.com

+ If your life is a hard drive, Christ can be your backup. +

Bruce Momjian wrote:

OK, then, I hope the following is accurate enough SGML to be more
useful. Submitted here per the instructions on
<http://www.postgresql.org/docs/8.3/interactive/bug-reporting.html

Good idea --- a table is certainly clearer. I modified your patch and
applied the attached version. Thanks much.

Hmm, I think the \\ and \' stuff should be part of that table too -- the
\<replaceable>a</> as in the patch seemed fine.

--
Alvaro Herrera http://www.CommandPrompt.com/
The PostgreSQL Company - Command Prompt, Inc.