Re: COPY for CSV documentation

Bruce Momjian wrote:

>Andrew Dunstan wrote:
>
>
>>In fact, in the patch I sent in, no quoted string is marked as null when
>>being read (so even if you use \N as the null marker, "\N" will be that
>>literal and not a null marker). And the null marker, whatever it is,
>>should be made quote safe by us throwing an error if it contains the
>>quote marker, just as we now make sure that the null marker is
>>delimiter-safe.
>>
>>
>
>What value does an int column get if the input file has ',,'. Don't
>tell me zero? :-) Error?
>
>

If the null marker is not an empty string, it gets an error, of course -
if it is it gets a null:

[andrew(at)marmaduke pginst]$ echo ',,' | bin/psql -c "create temp table
foo (a int, b text, c text); copy foo from stdin delimiter ',\"' null
'\\\\N';"
ERROR: invalid input syntax for integer: ""
CONTEXT: COPY foo, line 1, column a: ""
[andrew(at)marmaduke pginst]$ echo ',,' | bin/psql -c "create temp table
foo (a int, b text, c text); copy foo from stdin delimiter ',\"' ;"
[andrew(at)marmaduke pginst]$

I hope that is expected behaviour - it's what *I* expect, at least.

>
>
>>I will check on the write behaviour - it might need ammending too.
>>
>>I'll submit a revised patch based on the original syntax scheme, and
>>then you (Bruce) can make the syntax/psql changes that seem to be agreed
>>on now - is that ok?
>>
>>
>
>OK, go as far as you want and post it. I will turn around a new patch
>in a few hours after you post.
>
>
>
>>The default NULL value issue can be determined at the end of any
>>exhaustive debate we have - in the end it's a one line code change ;-)
>>
>>
>
>Agreed.
>
>
>

Attached patch has these additions to previously posted patch:
. quote character may not appear in NULL marker
. any non-null value that matches the NULL marker is forced to be quoted
when written.

cheers

andrew