diff options
author | Tom Lane | 2009-09-18 20:01:13 +0000 |
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committer | Tom Lane | 2009-09-18 20:01:13 +0000 |
commit | 04651daedf7c69f550c29c97238b121b255d89a1 (patch) | |
tree | 113b3a15023edd02e85df65b3e9036528b144cab | |
parent | 32ef0037ab702fd967072892a591ea6ac3d00314 (diff) |
A bit more wordsmithing on the COPY CSV NULL business.
-rw-r--r-- | doc/src/sgml/ref/copy.sgml | 17 |
1 files changed, 8 insertions, 9 deletions
diff --git a/doc/src/sgml/ref/copy.sgml b/doc/src/sgml/ref/copy.sgml index 859b0f924d..ea14a3d737 100644 --- a/doc/src/sgml/ref/copy.sgml +++ b/doc/src/sgml/ref/copy.sgml @@ -183,8 +183,8 @@ COPY { <replaceable class="parameter">tablename</replaceable> [ ( <replaceable c <listitem> <para> The string that represents a null value. The default is - <literal>\N</literal> (backslash-N) in text mode, and a empty - value with no quotes in <literal>CSV</> mode. You might prefer an + <literal>\N</literal> (backslash-N) in text mode, and an unquoted empty + string in <literal>CSV</> mode. You might prefer an empty string even in text mode for cases where you don't want to distinguish nulls from empty strings. </para> @@ -249,8 +249,7 @@ COPY { <replaceable class="parameter">tablename</replaceable> [ ( <replaceable c In <literal>CSV</> <command>COPY TO</> mode, forces quoting to be used for all non-<literal>NULL</> values in each specified column. <literal>NULL</> output is never quoted. If <literal>*</> is specified, - non-<literal>NULL</> values for all columns of the table will be - quoted. + non-<literal>NULL</> values will be quoted in all columns. </para> </listitem> </varlistentry> @@ -550,11 +549,11 @@ 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</> - parameter and is not quoted, while a non-NULL value matching the - the <literal>NULL</> parameter string is quoted. Therefore, using the default - settings, a <literal>NULL</> is written as an unquoted empty + <productname>PostgreSQL</>'s <command>COPY</> handles this by quoting. + A <literal>NULL</> is output as the <literal>NULL</> parameter string + and is not quoted, while a non-<literal>NULL</> value matching the + <literal>NULL</> parameter string is quoted. For example, with the + default settings, a <literal>NULL</> is written as an unquoted empty string, while an empty string data value is written with double quotes (<literal>""</>). Reading values follows similar rules. You can use <literal>FORCE NOT NULL</> to prevent <literal>NULL</> input |