Re: DBD::Pg exorts char columns with trailing blanks

On 10/18/19 9:19 AM, Adrian Klaver wrote:
> On 10/18/19 8:15 AM, Rob Sargent wrote:
>>
>> On 10/18/19 8:51 AM, Adrian Klaver wrote:
>>> On 10/18/19 7:42 AM, Matthias Apitz wrote:
>>>> El día viernes, octubre 18, 2019 a las 03:01:58p. m. +0200, Tom 
>>>> Lane escribió:
>>>>
>>>>> Matthias Apitz <guru@unixarea.de> writes:
>>>>>> When we export char columns with our Perl tools, they come out 
>>>>>> with trailing blanks (in Sybase they don't). Can this be suppressed?
>>>>>
>>>>> Switch to varchar, perhaps?
>>>>>
>>>>>             regards, tom lane
>>>>
>>>> Sometimes people does not know, what they propose. We have a 
>>>> historical
>>>> 25 years grown ILS which runs on top of Sybase, Oracle, Informix 
>>>> ... and
>>>> should now be ported to PostgreSQL. We can't simple switch internal
>>>> table structures and adopt some 10.000.000 lines of code (or debug 
>>>> while
>>>> it is now crashing).
>>>
>>> That was not mentioned in the original post. Anyway:
>>>
>>> https://metacpan.org/pod/DBD::Pg#ChopBlanks-(boolean,-inherited)
>>>
>>> https://metacpan.org/pod/DBI
>>>
>>> "ChopBlanks
>>>
>>> Type: boolean, inherited
>>>
>>> The ChopBlanks attribute can be used to control the trimming of 
>>> trailing space characters from fixed width character (CHAR) fields. 
>>> No other field types are affected, even where field values have 
>>> trailing spaces.
>>>
>>> The default is false (although it is possible that the default may 
>>> change). Applications that need specific behaviour should set the 
>>> attribute as needed.
>>>
>>> Drivers are not required to support this attribute, but any driver 
>>> which does not support it must arrange to return undef as the 
>>> attribute value."
>>>
>>>>
>>>> Thanks anyway.
>>>>
>>>>     matthias
>>>>
>>>>
>>>
>>>
>> It seems to me you've simply exposed a bug in you ILS.  If blanks 
>> intentionally went in, would they not get truncated on the way out in 
>> the other systems?  If all trailing blanks are expendable perhaps 
>> your saves should remove them.  (And a trimming of the existing 
>> records is in order.)
>
> The OP is dealing with char(acter) fields:
>
> https://www.postgresql.org/docs/11/datatype-character.html
>
> "If the string to be stored is shorter than the declared length, 
> values of type character will be space-padded; ..."
>
>>
>>
Understood
>>
>
>