Add E'' syntax so eventually normal strings can treat backslashes

literally.

Add GUC variables:

        "escape_string_warning" - warn about backslashes in non-E strings
        "escape_string_syntax" - supports E'' syntax?
        "standard_compliant_strings" - treats backslashes literally in ''

Update code to use E'' when escapes are used.

1 files changed, 56 insertions, 1 deletions

diff --git a/doc/src/sgml/runtime.sgml b/doc/src/sgml/runtime.sgml
index 4333445392..3841b0dee2 100644
--- a/doc/src/sgml/runtime.sgml
+++ b/doc/src/sgml/runtime.sgml
@@ -1,5 +1,5 @@
 <!--
-$PostgreSQL: pgsql/doc/src/sgml/runtime.sgml,v 1.330 2005/06/21 04:02:30 tgl Exp $
+$PostgreSQL: pgsql/doc/src/sgml/runtime.sgml,v 1.331 2005/06/26 03:03:17 momjian Exp $
 -->
 
 <chapter Id="runtime">
@@ -3757,6 +3757,30 @@ dynamic_library_path = 'C:\tools\postgresql;H:\my_project\lib;$libdir'
       </listitem>
      </varlistentry>
 
+     <varlistentry id="guc-escape-string-warning" xreflabel="escape_string_warning">
+      <term><varname>escape_string_warning</varname> (<type>boolean</type>)</term>
+      <indexterm><primary>strings</><secondary>escape</></>
+      <indexterm>
+       <primary><varname>escape_string_warning</> configuration parameter</primary>
+      </indexterm>
+      <listitem>
+       <para>
+        When <literal>on</>, a warning is issued if a backslash
+        (<literal>\</>) appears in a ordinary, non-escape syntax
+        (<literal>''</>) string. To log the statement that generated the
+        warning, set <varname>log_min_error_statement</> to
+        <literal>error</>.  The default is off.
+       </para>
+       <para>
+        Escape string syntax (<literal>E''</>) should be used for
+        escapes, because in future versions of
+        <productname>PostgreSQL</productname> ordinary strings will have
+        the standard-compliant behavior of treating backslashes
+        literally.
+       </para>
+      </listitem>
+     </varlistentry>
+
      </variablelist>
     </sect3>
     <sect3 id="runtime-config-compatible-clients">
@@ -3964,6 +3988,37 @@ dynamic_library_path = 'C:\tools\postgresql;H:\my_project\lib;$libdir'
       </listitem>
      </varlistentry>
 
+     <varlistentry id="guc-escape-string-syntax" xreflabel="escape_string_syntax">
+      <term><varname>escape_string_syntax</varname> (<type>boolean</type>)</term>
+      <indexterm><primary>strings</><secondary>escape</></>
+      <indexterm>
+       <primary><varname>escape_string_syntax</> configuration parameter</primary>
+      </indexterm>
+      <listitem>
+       <para>
+        Reports whether escape string syntax (<literal>E''</>) is
+        supported. This variable is used by applications that need to
+        determine if escape string syntax can be used in their code.
+       </para>
+      </listitem>
+     </varlistentry>
+
+     <varlistentry id="guc-sql-standard-strings" xreflabel="standard_compliant_strings">
+      <term><varname>standard_compliant_strings</varname> (<type>boolean</type>)</term>
+      <indexterm><primary>strings</><secondary>escape</></>
+      <indexterm>
+       <primary><varname>standard_compliant_strings</> configuration parameter</primary>
+      </indexterm>
+      <listitem>
+       <para>
+        Reports whether ordinary, non-escape syntax strings
+        (<literal>''</>) treat backslashes literally, as specified in
+        the SQL standard. This variable is used by applications that
+        need to know how ordinary strings are processed`.
+       </para>
+      </listitem>
+     </varlistentry>
+
     </variablelist>
    </sect2>