From 41a40fe4a2acc1256556754228a650610dbffa42 Mon Sep 17 00:00:00 2001
From: Bruce Momjian <bruce@momjian.us>
Date: Thu, 17 Sep 2009 21:13:01 +0000
Subject: [PATCH] CVS NULL Documentation
Clearify documentation of CVS's output of NULL values, per suggestion
from Magnus.
Backpatch to 8.4.X.
---
doc/src/sgml/ref/copy.sgml | 13 +++++--------
1 file changed, 5 insertions(+), 8 deletions(-)
diff --git a/doc/src/sgml/ref/copy.sgml b/doc/src/sgml/ref/copy.sgml
index 8ab9ff7ecae..ff91ee2d9f7 100644
--- a/doc/src/sgml/ref/copy.sgml
+++ b/doc/src/sgml/ref/copy.sgml
@@ -1,5 +1,5 @@
<!--
-$PostgreSQL: pgsql/doc/src/sgml/ref/copy.sgml,v 1.87 2009/09/05 23:58:01 tgl Exp $
+$PostgreSQL: pgsql/doc/src/sgml/ref/copy.sgml,v 1.88 2009/09/17 21:13:01 momjian Exp $
PostgreSQL documentation
-->
@@ -550,13 +550,10 @@ COPY <replaceable class="parameter">count</replaceable>
<para>
The <literal>CSV</> format has no standard way to distinguish a
<literal>NULL</> value from an empty string.
- <productname>PostgreSQL</>'s <command>COPY</> handles this by
- quoting. A <literal>NULL</> is output as the <literal>NULL</>
- string and is not quoted, while a data value matching the
- <literal>NULL</> string is quoted. Therefore, using the default
- settings, a <literal>NULL</> is written as an unquoted empty
- string, while an empty string is written with double quotes
- (<literal>""</>). Reading values follows similar rules. You can
+ <productname>PostgreSQL</>'s <command>COPY</> handles this using
+ quoting. A <literal>NULL</> is output as an empty string without
+ quotes, while an empty string data value is double-quoted
+ (<literal>""</>). Reading values follows similar rules. You can
use <literal>FORCE NOT NULL</> to prevent <literal>NULL</> input
comparisons for specific columns.
</para>
--
GitLab