Case insensitive utf8 select

Question

In SQLite I want to case-insensitive \"SELECT LIKE name\" works fine for normal latin names, but when the name is in UTF-8 with non-latin characters then the se

Answer 1

An improved version of LIKE overloading via a UDF:

$db->sqliteCreateFunction('like',
    function ($pattern, $data, $escape = null) use ($db)
    {
        static $modifiers = null;

        if (isset($modifiers) !== true)
        {
            $modifiers = ((strncmp($db->query('PRAGMA case_sensitive_like;')->fetchColumn(), '1', 1) === 0) ? '' : 'i') . 'suS';
        }

        if (isset($data) === true)
        {
            if (strpbrk($pattern = preg_quote($pattern, '~'), '%_') !== false)
            {
                $regex = array
                (
                    '~%+~S' => '.*',
                    '~_~S' => '.',
                );

                if (strlen($escape = preg_quote($escape, '~')) > 0)
                {
                    $regex = array
                    (
                        '~(? '.*',
                        '~(? '.',
                        '~(?:' . preg_quote($escape, '~') . ')([%_])~S' => '$1',
                    );
                }

                $pattern = preg_replace(array_keys($regex), $regex, $pattern);
            }

            return (preg_match(sprintf('~^%s$~%s', $pattern, $modifiers), $data) > 0);
        }

        return false;
    }
);

Respects the case_sensitive_like PRAGMA and correctly handles x LIKE y ESCAPE z syntax.

I also wrote another version that does basic and extended romanization of x and y values, so that an accented character will match it's unaccented counterpart, for instance: SELECT 'Á' LIKE 'à%';.

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