Re: finding rows with invalid characters

Sim, are you sure that encoding of the dump and the database
in which you are trying to restore it are same ?

2010/11/23 Sim Zacks <sim(at)compulab(dot)co(dot)il>

> Thanks for your help.
>
> I think a trigger will actually be the easiest. The way i can tell if there
> is invalid data is simply to do an Upper(text) and if it has invalid data it
> fails.
>
> I dumped the fixed database. Now I have a years worth of backups that I
> can't restore a specific table from. It most probably will never mean
> anything. Every once in a while, I get asked to check what was in the db
> against what is in there, but this table will probably never be audited.
>
>
> Sim
>
>
>
> On 11/23/2010 10:33 AM, Dmitriy Igrishin wrote:
>
> Hey Sim,
>
> 2010/11/23 Sim Zacks <sim(at)compulab(dot)co(dot)il>
>
>> On 11/21/2010 05:55 PM, Dmitriy Igrishin wrote:
>>
>> Hey Sim,
>>
>> Maybe this helps:
>>
>> http://blog.tapoueh.org/articles/blog/_Getting_out_of_SQL_ASCII,_part_2.html
>>
>> That worked to find some of them. I still needed to find a bunch of
>> others manually, such as 0xa0 and 0xd725 which weren't found with that
>> function. I finally figured out that
>> select * from emaildetails where emailbody like '%\xa0%' and
>> select * from emaildetails where emailbody like '%\xd7\x25%' would show me
>> all those rows.
>>
>> My 2 big problems now are:
>>
>> A) how to make sure that these chars are not inserted in the future. The
>> database should prevent them from being inserted.
>>
> Consider to use domains -- generic-based types with constraints -- instead
> of generic types.
> Use regular expressions in constraints.
> As alternative, you can use triggers for more complex validation. But
> domains in you case
> IMO will work good.
>
>
>> B) How to fix the backups that I have so that I can restore them. As I
>> mentioned, they are being taken with -Fc
>>
> Oops. Why not dump fixed database ?
>
>>
>> Sim
>>
>>
>>
>> 2010/11/21 Sim Zacks <sim(at)compulab(dot)co(dot)il>
>>
>>> I am using PG 8.2.17 with UTF8 encoding.
>>> "PostgreSQL 8.2.17 on i686-pc-linux-gnu, compiled by GCC gcc (GCC) 4.1.1
>>> (Gentoo 4.1.1)"
>>>
>>> One of my tables somehow has invalid characters in it:
>>>
>>>> ERROR: invalid byte sequence for encoding "UTF8": 0xa9
>>>> HINT: This error can also happen if the byte sequence does not match
>>>> the encoding expected by the server, which is controlled by
>>>> "client_encoding".
>>>>
>>> I have already manually found a number of the bad rows by running queries
>>> with text functions (upper) between groups of IDs until I found the specific
>>> bad row.
>>>
>>> 1) Is there a quicker way to get a list of all rows with invalid
>>> characters
>>> 2) Shouldn't the database prevent these rows from being entered in the
>>> first place?
>>> 3) I have backups of this database (using -Fc) and I noticed that on
>>> restore, this table is not restored because of this error. Is there a way to
>>> fix the existing backups, or tell the restore to ignore bad rows instead of
>>> erroring out the whole table?
>>>
>>> Thanks
>>> Sim
>>>
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>>
>>
>>
>> --
>> // Dmitriy.
>>
>>
>>
>>
>
>
> --
> // Dmitriy.
>
>
>
>

--
// Dmitriy.