Question

我有以下查询。如何使用“ spendamount”，“ winamount” 在2个查询的结果之间进行减法。当我减去（spendamount-winamount）时，出现以下错误：

1054-“字段列表”中的未知列“ spendamount”

SELECT tbl_customers.*,
IFNULL((SELECT sum(win_amount) FROM `tbl_cricket_customer_contests` where customer_id=tbl_customers.id), 0) as winamount,
(SELECT SUM(tcc.entry_fees) as amount FROM tbl_cricket_customer_contests tccc JOIN tbl_cricket_contest_matches tccm ON tccm.id = tccc.match_contest_id JOIN tbl_cricket_contests tcc ON tcc.id = tccm.contest_id WHERE tccc.customer_id = tbl_customers.id ) as spendamount,
(spendamount-winamount)
FROM (`tbl_customers`) 
WHERE `tbl_customers`.`is_deleted` = 'N' 
GROUP BY `tbl_customers`.`id` 
ORDER BY `spendamount` DESC

Answer 1

请重写查询，以使用联接获取总数量：

SELECT t.*,
    COALESCE(c.win_amount, 0) AS winamount,
    COALESCE(tccc.amount, 0) AS spendamount,
    (COALESCE(tccc.amount, 0) - COALESCE(c.win_amount, 0)) AS diff
FROM tbl_customers t
LEFT JOIN
(
    SELECT customer_id, SUM(win_amount) AS win_amount
    FROM tbl_cricket_customer_contests
    GROUP BY customer_id
) c
    ON c.customer_id = t.id
LEFT JOIN
(
    SELECT customer_id, SUM(tcc.entry_fees) as amount
    FROM tbl_cricket_customer_contests tccc
    INNER JOIN tbl_cricket_contest_matches tccm
        ON tccm.id = tccc.match_contest_id
    INNER JOIN tbl_cricket_contests tcc
        ON tcc.id = tccm.contest_id
) tccc
    ON tccc.customer_id = t.id
WHERE
    t.is_deleted = 'N' 
ORDER BY
    spendamount DESC;

Answer 2

使用实际表达式代替别名，也可以使用子查询

select *,spendamount-winamount from 
( 
   SELECT tbl_customers.*,
    IFNULL((SELECT sum(win_amount) FROM `tbl_cricket_customer_contests` where customer_id=tbl_customers.id), 0) as winamount,
    (SELECT SUM(tcc.entry_fees) as amount FROM tbl_cricket_customer_contests tccc JOIN tbl_cricket_contest_matches tccm ON tccm.id = tccc.match_contest_id JOIN tbl_cricket_contests tcc ON tcc.id = tccm.contest_id WHERE tccc.customer_id = tbl_customers.id ) as spendamount
    FROM (`tbl_customers`) 
    WHERE `tbl_customers`.`is_deleted` = 'N' 

)A

Answer 3

请尝试此查询。

SELECT AA.*,AA.spendamount - AA.winamount As Amount FROM 
(
SELECT tbl_customers.*,
IFNULL((SELECT sum(win_amount) FROM `tbl_cricket_customer_contests` where customer_id=tbl_customers.id), 0) as winamount,
(SELECT SUM(tcc.entry_fees) as amount FROM tbl_cricket_customer_contests tccc JOIN tbl_cricket_contest_matches tccm ON tccm.id = tccc.match_contest_id JOIN tbl_cricket_contests tcc ON tcc.id = tccm.contest_id WHERE tccc.customer_id = tbl_customers.id ) as spendamount,
(spendamount-winamount)
FROM (`tbl_customers`) 
WHERE `tbl_customers`.`is_deleted` = 'N' 
GROUP BY `tbl_customers`.`id` 
ORDER BY `spendamount` DESC
)As AA

如何使用子查询导致减法？

3 个答案: