<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>
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>
<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