From 1c51c7d5ffd407426f314b2cd317ef77f14efb1f Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <peter_e@gmx.net>
Date: Tue, 22 Feb 2011 23:33:44 +0200
Subject: Add PL/Python functions for quoting strings
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Add functions plpy.quote_ident, plpy.quote_literal,
plpy.quote_nullable, which wrap the equivalent SQL functions.

To be able to propagate char * constness properly, make the argument
of quote_literal_cstr() const char *.  This also makes it more
consistent with quote_identifier().

Jan Urbański, reviewed by Hitoshi Harada, some refinements by Peter
Eisentraut
---
 doc/src/sgml/plpython.sgml | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

(limited to 'doc/src')

diff --git a/doc/src/sgml/plpython.sgml b/doc/src/sgml/plpython.sgml
index e05c2937b1f..7c869a8719f 100644
--- a/doc/src/sgml/plpython.sgml
+++ b/doc/src/sgml/plpython.sgml
@@ -997,6 +997,23 @@ $$ LANGUAGE plpythonu;
    <xref linkend="guc-client-min-messages"> configuration
    variables. See <xref linkend="runtime-config"> for more information.
   </para>
+
+  <para>
+   Another set of utility functions are
+   <literal>plpy.quote_literal(<replaceable>string</>)</literal>,
+   <literal>plpy.quote_nullable(<replaceable>string</>)</literal>, and
+   <literal>plpy.quote_ident(<replaceable>string</>)</literal>.  They
+   are equivalent to the built-in quoting functions described in <xref
+   linkend="functions-string">.  They are useful when constructing
+   ad-hoc queries.  A PL/Python equivalent of dynamic SQL from <xref
+   linkend="plpgsql-quote-literal-example"> would be:
+<programlisting>
+plpy.execute("UPDATE tbl SET %s = %s where key = %s" % (
+    plpy.quote_ident(colname),
+    plpy.quote_nullable(newvalue),
+    plpy.quote_literal(keyvalue)))
+</programlisting>
+  </para>
  </sect1>
 
  <sect1 id="plpython-envar">
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