Re: finding rows with invalid characters

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 <mailto: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 <mailto: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.
>
>