Re: query to match '\N'

Nis Jørgensen wrote:
> Alban Hertroys skrev:
>
>> Presumably he wanted col2 like E'%\\\\N%'.
>> But doesn't \N mean NULL, or would the OP be looking for literal '\N'
>> strings in his data? Because if he's looking for NULLs it may be better
>> to query for col2 IS NULL.
>
> My guess is that this string was used to signify NULL in the file
> originally imported into the db.

Which is basically what I was pointing out ;)
It's all speculation anyway, we're guessing at what problem the OP tries
to solve.

I think either he is looking for NULL column values that exist in his
input file as '\N' strings (strings cannot contain NULLs, so using
"like" is pointless), or he is looking for failed conversions of \N from
his input file that thus may have ended up as literal \N characters in
column data.

In the latter case there shouldn't be any columns that match "like
'%\\\\N%'" but not "= '\\\\N'". OTOH, we may be talking about an import
failure, in which case anything is possible. Fixing that would probably
be more difficult than fixing the cause of the failure and re-doing the
import.

As I said, it's all speculation. Without input from the OP there's not
much point in continuing this discussion.

Regards,
--
Alban Hertroys
alban(at)magproductions(dot)nl

magproductions b.v.

T: ++31(0)534346874
F: ++31(0)534346876
M:
I: www.magproductions.nl
A: Postbus 416
7500 AK Enschede

// Integrate Your World //