Re: GROUP_CONCAT question

[laptop alias]

CREATE TABLE order_info
( order_id INT NOT NULL
, product_id INT NOT NULL
, option_attribute VARCHAR(20)
, option_value VARCHAR(20)
, PRIMARY KEY(order_id,product_id,option_attribute,option_value)
);

INSERT INTO order_info VALUES 
(1,10,'Colour','Red'),
(1,10,'Size','Large'),
(1,10,'Sleeve','Short'),
(2,10,'Colour','Blue'),
(2,10,'Size','Small'),
(2,10,'Sleeve','Long');

SELECT order_id `Order`
     , product_id Product
     , MAX(CASE WHEN option_attribute = 'Colour' THEN option_value END) Colour 
     , MAX(CASE WHEN option_attribute = 'Size'   THEN option_value END) Size
     , MAX(CASE WHEN option_attribute = 'Sleeve' THEN option_value END) Sleeve
  FROM order_info 
 GROUP 
    BY order_id
     , product_id;
+-------+---------+--------+-------+--------+
| Order | Product | Colour | Size  | Sleeve |
+-------+---------+--------+-------+--------+
|     1 |      10 | Red    | Large | Short  |
|     2 |      10 | Blue   | Small | Long   |
+-------+---------+--------+-------+--------+

Note that this kind of thing is normally handled at the application level (e.g. with a bit of PHP) - oh, and the EAV model is sometimes discouraged!