Symfony 2 / Doctrine用户定义的DQL函数参数是否有字符串长度限制？

Question

I created my custom DQL function for Doctrine DQL:

class Translate extends FunctionNode {
    public $field;

    public function getSql(SqlWalker $sqlWalker) {
        $query = "TRANSLATE(" . $this->field->dispatch($sqlWalker) . ", 'àâäãáåÀÁÂÃÄÅçÇéèêëÉÈÊËîïìíÌÍÎÏñÑôöðòóÒÓÔÕÖùúûüÙÚÛÜýÿÝ', 'AAAAAAAAAAAACCEEEEEEEEIIIIIIIINNOOOOOOOOOOUUUUUUUUYYY')";
        return $query;
    }

    public function parse(Parser $parser) {
        $parser->match(Lexer::T_IDENTIFIER);
        $parser->match(Lexer::T_OPEN_PARENTHESIS);
        $this->field = $parser->StringPrimary();
        $parser->match(Lexer::T_CLOSE_PARENTHESIS);
    }
}

It seems to work well when using it.

But if the string parameter contains more than 307 chars, it is not working. There is no error but the script is ending.

$query = $this->createQueryBuilder('...');
$query->addSelect("TRANSLATE('less than 307 chars')"); // working
$query->addSelect("TRANSLATE('more than 307 chars')"); // NOT working

How can I use more than 307 chars?

Answer 1

Like wrikken had already explained, Transliteration should be done using iconv since that will save your server resources.

here's a simple function that will transliterate (convert non latin characters to their closest representations in latin charset) a string.

function transliterateString($str)
{
    $serverLocale = setlocale(LC_CTYPE, 0);
    setlocale(LC_CTYPE, 'en_US.UTF8');
    // transliterate the string using iconv
    $str = iconv('UTF-8', 'ASCII//TRANSLIT//IGNORE', $str); 
    setlocale(LC_CTYPE, $serverLocale); //  return the locale to what it was before
    return $str;
}   

Usage:

$string = "café"; 
echo $string;
echo transliterateString($string);

Above will output the below:

café
cafe