$sql = "SELECT
    s.*,
    co.name AS county,

    ROUND ( AVG(r.rating ), 1 ) as rating_avg,

    CONCAT('[',
        COALESCE(
            GROUP_CONCAT(
                DISTINCT
                CONCAT('\"',c.name,'\"')
                ORDER BY c.name ASC
                SEPARATOR ','
            ),
        ''),
    ']') AS categories,

    CONCAT('[',
        COALESCE(
            GROUP_CONCAT(
                DISTINCT
                CONCAT('{
                    \"user\":\"',u.nickname,'\",
                    \"rating\":\"',r.rating,'\",
                    \"date\":\"',r.date,'\",
                    \"comment\":\"',
                        REPLACE(
                            REPLACE(r.comment, '\n', '\\\\n'),
                            '\"', '\\\\\"' ),'\"
                }')
                SEPARATOR ','
            ),
        ''),
    ']') AS ratings

    FROM services s

    JOIN ratings r ON r.service_id = s.id
    JOIN users u ON u.user_id = r.user_id
    JOIN category_relationships cr ON cr.service_id = s.id
    JOIN categories c ON c.id = cr.category_id
    JOIN counties co ON co.id = s.county

    WHERE s.id = '$sid' ";