truekenny

SELECT @id:=0;
SELECT 
	@id:=@id+1 as id,
	A.`time`, 
	IFNULL(UNIX_TIMESTAMP(A2.`time`)-UNIX_TIMESTAMP(A.`time`), 0) as dura, 
	A.type
FROM A
LEFT JOIN A A2
ON A.id + 1 = A2.id
WHERE
	MOD(A.id, 2) = 1 
	AND A.`time` BETWEEN '2013-01-01' AND '2014-01-01';