Pobieranie wiersza z danymi z tabeli par klucz-wartość w MySQL

Spróbuj tego:

SELECT `customer`.*, `ca1`.`value1` AS `wedding_date`, `ca2`.`value1` AS `test` 
FROM `customer` 
LEFT JOIN `customer_attributes` AS `ca1` ON customer.customerID = ca1.customerID  AND ca1.key1='wedding_date'
LEFT JOIN `customer_attributes` AS `ca2` ON customer.customerID = ca2.customerID AND ca2.key1='test'
WHERE (customer.customerID = '58029') 

Przeniesienie warunków 2 WHERE z ca1/ca2 do warunku JOIN powinno to posortować