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author | Bruce Momjian <bruce@momjian.us> | 2009-09-17 21:28:30 +0000 |
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committer | Bruce Momjian <bruce@momjian.us> | 2009-09-17 21:28:30 +0000 |
commit | 77b2388b2417d80505db67a81f773cf80e2d9529 (patch) | |
tree | f1eb283e8ba2a7b55cc98fdab23d0075b3ac3f17 | |
parent | 010394d7aa4eadb9ec6ba8f1175e7e043ae3d01f (diff) | |
download | postgresql-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.sgml | 15 |
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> |