protected function get_select_search_in_column($columnname) {
        global $DB;

        if ($DB->sql_regex_supported()) {
            // Database supports regex, use it for better match.
            $select = $columnname . ' ' . $DB->sql_regex() . ' ?';
            $params = ["(src|data)\ *=\ *[\\\"\']http://"];
        } else {
            // Databases without regex support should use case-insensitive LIKE.
            // This will have false positive matches and more results than we need, we'll have to filter them in php.
            $select = $DB->sql_like($columnname, '?', false);
            $params = ['%=%http://%'];
        }

        return [$select, $params];
    }