mysql - SQL : Group a Union

Question

我有以下查询，它总是给我两行。我想使用 tbluser.userid 将它们分组为一行，是否可以分组联合？

SELECT
SUM(tblfooditem.calories)
FROM tblfooditem
INNER JOIN tbluser ON tblfooditem.userid = tbluser.userid
WHERE tblfooditem.userid=?userid AND tblfooditem.date=?date
GROUP BY tbluser.userid
UNION
SELECT
SUM(tbladdedmealitem.calories)
FROM tbladdedmeal
INNER JOIN tbluser ON tbladdedmeal.userid = tbluser.userid
WHERE tbladdedmeal.userid=?userid AND tbladdedmeal.date=?date
GROUP BY tbluser.userid;

Answer 1

这是可能的。

select sum(s) from (
SELECT
    SUM(tblfooditem.calories) S,tbl.userid
    FROM tblfooditem
    INNER JOIN tbluser ON tblfooditem.userid = tbluser.userid
    WHERE tblfooditem.userid=?userid AND tblfooditem.date=?date
    GROUP BY tbluser.userid
    UNION
    SELECT
    SUM(tbladdedmealitem.calories) S,tbl.userid
    FROM tbladdedmeal
    INNER JOIN tbluser ON tbladdedmeal.userid = tbluser.userid
    WHERE tbladdedmeal.userid=?userid AND tbladdedmeal.date=?date
    GROUP BY tbluser.userid
) Q
group by Q.userid