MySql CONCATENATE result of UNION

Question

I want to have a result concatenate from a result of a union of query... my code is this:

SELECT GROUP_CONCAT(rifDoc), idUser, user, dateDoc
FROM
(
SELECT GROUP_CONCAT(CAR.rifDoc) AS rifDoc, CAR.idUser, CAR.user, CARDETT.dateDoc
FROM car AS CAR, carDett AS CARDETT 
WHERE CAR.id>0 CAR.id=CARDETT.idDoc CARDETT.dateDoc<='2017-01-31' 
GROUP BY idUser, dateDoc

UNION ALL

SELECT GROUP_CONCAT(BK.rifDoc) AS rifDoc, BK.idUser, BK.user, GROUP_CONCAT(BK.inUso) AS inUso, GROUP_CONCAT(BK.inCarico) AS inCarico, BKDETT.dateDoc
FROM bike AS BK, bikeDett AS BKDETT 
WHERE BK.id>0 AND BK.id=BKDETT.idDoc AND BKDETT.dateDoc<='2017-01-31' 
GROUP BY idUser, dateDoc
 )

GROUP BY idUser, dateDoc

But I have an error like this:

#1248 - Every derived table must have its own alias

Someone have a solutions?

Answer 1

You are missing an alias for the inline view or subquery as the error states like

SELECT GROUP_CONCAT(rifDoc), idUser, `user`, dateDoc
FROM
(
SELECT GROUP_CONCAT(CAR.rifDoc) AS rifDoc, CAR.idUser, CAR.user, CARDETT.dateDoc
FROM car AS CAR, carDett AS CARDETT 
WHERE CAR.id>0 CAR.id=CARDETT.idDoc CARDETT.dateDoc<='2017-01-31' 
GROUP BY idUser, dateDoc

UNION ALL

SELECT GROUP_CONCAT(BK.rifDoc) AS rifDoc, BK.idUser, BK.user, GROUP_CONCAT(BK.inUso) AS inUso, GROUP_CONCAT(BK.inCarico) AS inCarico, BKDETT.dateDoc
FROM bike AS BK, bikeDett AS BKDETT 
WHERE BK.id>0 AND BK.id=BKDETT.idDoc AND BKDETT.dateDoc<='2017-01-31' 
GROUP BY idUser, dateDoc
 ) XXX     <--- here