Re: Fixed chars

From: Enrico Pirozzi <e(dot)pirozzi(at)nbsgroup(dot)it>
To: pgsql-general(at)lists(dot)postgresql(dot)org
Subject: Re: Fixed chars
Date: 2018-03-28 09:53:17
Message-ID: 7947a8b7-a908-3976-eb02-2810e480a267@nbsgroup.it
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Resolved...my missing

Thanks

Enrico

https://www.postgresql.org/docs/10/static/datatype-character.html

"Values of type|character|are physically padded with spaces to the
specified width/|n|/, and are stored and displayed that way. However,
trailing spaces are treated as semantically insignificant and
disregarded when comparing two values of type|character|. In collations
where whitespace is significant, this behavior can produce unexpected
results; for example|SELECT 'a '::CHAR(2) collate "C" <
E'a\n'::CHAR(2)|returns true, even though|C|locale would consider a
space to be greater than a newline. Trailing spaces are removed when
converting a|character|value to one of the other string types. Note that
trailing spaces/are/semantically significant in|character
varying|and|text|values, and when using pattern matching, that
is|LIKE|and regular expressions."

Il 28/03/2018 11:32, Andreas Kretschmer ha scritto:
>
>
> Am 28.03.2018 um 11:11 schrieb Enrico Pirozzi:
>> Hi , I've seen this strange thing.
>>
>> sitedb=# create table test_tb(codice char(7));
>> CREATE TABLE
>> sitedb=# insert into test_tb values('pippo');
>> INSERT 0 1
>> sitedb=# select codice || 'a'::char(1),length(codice) from test_tb
>> ?column? | length
>> ----------+--------
>> pippoa | 5
>> (1 row)
>>
>
> where is the problem? length() returns the number of chars in string,
> and the string in codice is 5 chars long.
>
>
>>
>> On the official documentation
>>
>> |character(/|n|/)|,|char(/|n|/)| fixed-length, blank padded
>>
>> https://www.postgresql.org/docs/10/static/datatype-character.html
>
> test=*# select length('12345'::char(10)),
> pg_column_size('12345'::char(10));
> length | pg_column_size
> --------+----------------
> 5 | 14
> (1 Zeile)
>
>
>
> helps that?
>
>
> Regards, Andreas
>

--
Enrico Pirozzi
NBS Group S.r.l.
via Val Tiberina 23/A
63074, San Benedetto del Tronto (AP)
Tel. 0735-7626201

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