diff options
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/ref/copy.sgml | 23 |
1 files changed, 17 insertions, 6 deletions
diff --git a/doc/src/sgml/ref/copy.sgml b/doc/src/sgml/ref/copy.sgml index 83a51362c5b..c8e4debea71 100644 --- a/doc/src/sgml/ref/copy.sgml +++ b/doc/src/sgml/ref/copy.sgml @@ -1,5 +1,5 @@ <!-- -$Header: /cvsroot/pgsql/doc/src/sgml/ref/copy.sgml,v 1.52 2003/09/30 01:56:11 tgl Exp $ +$Header: /cvsroot/pgsql/doc/src/sgml/ref/copy.sgml,v 1.53 2003/10/06 02:38:53 tgl Exp $ PostgreSQL documentation --> @@ -257,7 +257,7 @@ COPY <replaceable class="parameter">tablename</replaceable> [ ( <replaceable cla Columns in a row are separated by the delimiter character. The column values themselves are strings generated by the output function, or acceptable to the input function, of each - attribute's data type. The specified null-value string is used in + attribute's data type. The specified null string is used in place of columns that are null. <command>COPY FROM</command> will raise an error if any line of the input file contains more or fewer columns than are expected. @@ -283,6 +283,15 @@ COPY <replaceable class="parameter">tablename</replaceable> [ ( <replaceable cla </para> <para> + The specified null string is sent by <command>COPY TO</command> without + adding any backslashes; conversely, <command>COPY FROM</command> matches + the input against the null string before removing backslashes. Therefore, + a null string such as <literal>\N</literal> cannot be confused with + the actual data value <literal>\N</literal> (which would be represented + as <literal>\\N</literal>). + </para> + + <para> The following special backslash sequences are recognized by <command>COPY FROM</command>: @@ -335,10 +344,12 @@ COPY <replaceable class="parameter">tablename</replaceable> [ ( <replaceable cla </para> <para> - Never put a backslash before a data character <literal>N</> or period - (<literal>.</>). Such pairs will be mistaken for the default null string - or the end-of-data marker, respectively. Any other backslashed character - that is not mentioned in the above table will be taken to represent itself. + Any other backslashed character that is not mentioned in the above table + will be taken to represent itself. However, beware of adding backslashes + unnecessarily, since that might accidentally produce a string matching the + end-of-data marker (<literal>\.</>) or the null string (<literal>\N</> by + default). These strings will be recognized before any other backslash + processing is done. </para> <para> |