如何在Perl ASP SQLite数据库中保存®（注册商标）

Question

I can not isolate this problem. I have an HTML form text input that is being saved into an SQLite datebase via Perl ASP. If I just save the form data ® or if replace the character by using:

    $registered = chr(174);
$DESCRIPTION =~ s/$registered/R/g;

I get an extra character when the data is retreived ® or ÂR if I replace the trademark with the code above, save it again and I get î , again ÃÂî . Where are the ÃÂ 's coming from??

Answer 1

Set the sqlite_unicode attribute to 1 in your connect:

$dbh = DBI::connect( "dbi:SQLite:dbname=foo", "", "", { sqlite_unicode => 1 } );

After that, when setting some binary data columns, you may need to explicitly denote them as binary:

$sth->bind_param(1, $binary_data, SQL_BLOB);

Answer 2

The string is probably in UTF-8 (Perl's standard for character encoding) when you are working with it. A registered trademark symbol in UTF-8 is two bytes, and you are only replacing one of them. See more information here for the encoding of that character .

If you want to replace the symbol with a regex, use a method other than chr() to match the appropriate character. You should be able to do this:

s/\x{c2ae}/R/g;

\\x matches a UTF-8 character given in hexadecimal. I obtained the hex encoding from the page linked above.

For more information see "Escape Sequences" in perlre .

Also see the Encode core module for more information on how Perl handles character encodings.

Answer 3

Maybe this tour will shed some light on what you are hitting? I'm guessing chr2 is where your issue lies.

use strictures;
use utf8;
use DBI;

my $dbh = DBI->connect("dbi:SQLite::memory:", undef, undef,
                       { sqlite_unicode => 1,
                         PrintError => 1 } );

$dbh->do(<<"");
   CREATE TABLE moo (
    name TEXT
    ,string TEXT )

my $insert = $dbh->prepare("INSERT INTO moo VALUES ( ?, ? )");

my %reg = ( raw => "®", # note "use utf8;"
            "chr" => chr(174) );

while ( my ( $name, $reg ) = each %reg )
{
    $insert->execute($name, $reg);
}

# And a couple without placeholders (which we all know is EVIL, right?)
$dbh->do(<<"");
    INSERT INTO moo VALUES( "raw2", "®" )

my $reg = chr(174);
$dbh->do(<<"");
    INSERT INTO moo VALUES( "chr2", "$reg" )

my $sth = $dbh->prepare("SELECT * FROM moo");

$sth->execute;

binmode STDOUT, ":encoding(UTF-8)";
while ( my $row = $sth->fetchrow_hashref )
{
    print $row->{name}, " -> ", $row->{string}, $/;
}

__DATA__
chr -> ®
raw -> ®
raw2 -> ®
"\x{00ae}" does not map to utf8.
chr2 -> \xAE

Answer 4

After taking a look at the characters actually in the string with:

foreach (split //, $DESCRIPTION) {
     $hold = ord($_);
     %>chr(<%= $hold %>)<br><%
}

I found that ® from the html form text input is being treated/received as chr(194).chr(174). So:

    $registered = chr(194).chr(174);
$DESCRIPTION =~ s/$registered/®/g;

allows me to save it to the database without issue...