MySQL concat multiple rows into a single row

Question

I have a query that returns multiple rows such as below in MySQL:

attribute_name  value
----------------------------------------
username          emailuser
domain          mydomain.com

My Required output is as follows:

username       domain
-----------------------------
emailuser     mydomain.com

Current SQL:

    SELECT pa2.attribute_name, upa2.value
      FROM product p

INNER JOIN product_attribute pa ON p.product_id = pa.product_id
       AND pa.attribute_name = 'alias'

INNER JOIN user_product_attribute upa ON pa.product_attribute_id upa.product_attribute_id

INNER JOIN user_product_attribute upa2 ON upa.user_product_id = upa2.user_product_id

INNER JOIN product_attribute pa2 ON pa2.product_attribute_id = upa2.product_attribute_id
    AND pa2.attribute_name
    IN (
    'username', 'domain'
    )

WHERE p.product_name = 'email'
AND upa.value = 'emailalias@domainalias'

I have been looking at group_concat, but i think that is the wrong path.. Any suggestions?

Answer 1

Nothing wrong with group_concat . The following query will be slow but for a small table, that might not matter so much.

SELECT 
GROUP_CONCAT(IF(`attribute_name`='username', `value`,'')) AS `username`,
GROUP_CONCAT(IF(`attribute_name`='domain', `value`, '')) AS `domain`,
FROM (your old table or the select query)
GROUP BY `attribute_name`