I'm going to describe how DBD::mysql works. I suspect DBD::Pg works the same way.

---

Perl has two ways of storing strings. DBI or DBD::mysql looks at the internal buffer of scalars without checking which storage format was used, so every time you pass a string, it's as if you actually passed

use Encode qw( is_utf8 encode_utf8 );

is_utf8($string) ? encode_utf8($string) : $string
[download]

This is a bug, but it almost always does the right thing.

---

Workaround:

• If you have a decoded string (a string of Unicode code points), you can use the following:

  use Encode qw( encode_utf8 );
  
  $dbh->do("SET NAMES utf8");
  
  my $sth = ...;
  $sth->execute(encode_utf8($decoded));
  [download]

• If you have a string encoded using cp1252, you can use the following:

  use Encode qw( decode );
  
  $dbh->do("SET NAMES utf8");
  
  my $sth = ...;
  $sth->execute(decode('cp1252', $encoded));
  [download]

• If you have a string encoded using cp1252 you want to avoid any encoding and decoding on the Perl side, you can use the following:

  sub _d { my ($s) = @_; utf8::downgrade($_); $s }
  
  $dbh->do("SET NAMES cp1252");
  
  my $sth = ...;
  $sth->execute(_d($encoded));
  [download]

Notes:

• Passing mysql_enable_utf8=>1 to DBI->connect does $dbh->do("SET NAMES utf8"); for you. Later changes to mysql_enable_utf8 does not.
• is_utf8 always returns true for strings returned by Encode::decode and Encode::decode_utf8.
• is_utf8 always returns false for strings returned by Encode::encode, Encode::encode_utf8 and Encode::from_to.

---

---

Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!

Titles consisting of a single word are discouraged, and in most cases are disallowed outright.

Read Where should I post X? if you're not absolutely sure you're posting in the right place.

Please read these before you post! —

• How do I compose an effective node title?
• How do I post a question effectively?
• Markup in the Monastery

Posts may use any of the Perl Monks Approved HTML tags:

a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr

You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)

	For:		Use:
	&		&
	<		&lt;
	>		&gt;
	[		&#91;
	]		&#93;

Link using PerlMonks shortcuts! What shortcuts can I use for linking?

See Writeup Formatting Tips and other pages linked from there for more info.