𓏞מילים דיגיטליות

Problem

I see question marks instead of non-latin UTF8 characters reading MySQL database using PHP. For instance, my Latvian, Slovak or Hebrew characters in a WordPress blog has gone all "??????".

Longer and more formally:
Let [DB] be a MySQL (4.1, or other(?)) database in which the encoding is, say, UTF8.
Let [PHP] be a PHP (5, or other(?)) file which makes a query using the [DB] database.
Now, if one doesn't set the proper settings, there might be a problem reading non-latin1 characters from [DB] using [PHP], in some configurations. In this case, a question-mark will be shown instead of every byte written non-latin1ly. Since unicode use two-byted characters most frequently, one will see "??" instead of, say, "א" or "ř".

Solution

In WordPress, edit the wp-includes/wp-db.php file and add the following lines before retrieving the data (using the $this->select($dbname); line), replacing the CHARSET with the name of the encoding you use (most likely UTF8):

$res = @mysql_query('SET character_set_results='.CHARSET, $this->dbh);
$res = @mysql_query('SET character_set_connection='.CHARSET, $this->dbh);
$res = @mysql_query('SET character_set_client='.CHARSET, $this->dbh);

If you've got the same problem not using WordPress, make similiar @mysql_query-s, according to the variable-names you use.