aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorBruce Momjian <bruce@momjian.us>2009-09-17 21:28:30 +0000
committerBruce Momjian <bruce@momjian.us>2009-09-17 21:28:30 +0000
commit77b2388b2417d80505db67a81f773cf80e2d9529 (patch)
treef1eb283e8ba2a7b55cc98fdab23d0075b3ac3f17
parent010394d7aa4eadb9ec6ba8f1175e7e043ae3d01f (diff)
downloadpostgresql-77b2388b2417d80505db67a81f773cf80e2d9529.tar.gz
postgresql-77b2388b2417d80505db67a81f773cf80e2d9529.zip
CVS NULL Documentation
Clearify documentation of CVS's output of NULL values, per suggestion from Magnus. Backpatch to 8.4.X.
-rw-r--r--doc/src/sgml/ref/copy.sgml15
1 files changed, 6 insertions, 9 deletions
diff --git a/doc/src/sgml/ref/copy.sgml b/doc/src/sgml/ref/copy.sgml
index e7f76d3e581..238397828fe 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 1.85 2009/02/06 21:22:49 tgl Exp $
+$PostgreSQL: pgsql/doc/src/sgml/ref/copy.sgml,v 1.85.2.1 2009/09/17 21:28:30 momjian Exp $
PostgreSQL documentation
-->
@@ -541,16 +541,13 @@ COPY <replaceable class="parameter">count</replaceable>
non-<literal>NULL</> values in specific columns.
</para>
- <para>
+ <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>