mysql select if sum greater 和 group by

Question

我有两个 mysql 表。 第一张表:

cost_id| cost_customer_id | cost_total | cost_date
 1     |      1           |     50     | 2019-01-03
 2     |      2           |    120     | 2019-02-03
 3     |      1           |     70     | 2019-03-21
 4     |      2           |     35     | 2019-04-03
 5     |      3           |     14     | 2019-05-07
 6     |      1           |     84     | 2019-06-03

第二张表:

inv_id | inv_customer_id  | inv_total  | inv_date
 1     |      1           |    150     | 2019-01-05
 2     |      2           |     20     | 2019-02-06
 3     |      1           |     90     | 2019-03-21
 4     |      1           |      3     | 2019-04-03
 5     |      3           |     94     | 2019-05-09
 6     |      2           |     11     | 2019-06-08
 7     |      1           |     99     | 2019-07-06
 8     |      2           |     71     | 2019-08-04
 9     |      1           |     45     | 2019-09-02

所以我想要返回的是:

customer_id | sum_inv_total | sum_cost_total  | balance     | avg_inv_date
     1      |      387      |     204         |   183       | 2019-05-31
     2      |      102      |     155         |   -53       | null
     3      |       94      |      14         |    80       | 2019-05-09

即，在扣除由 inv_date 订购的成本后获得每个客户的平均 inv_date，例如客户 #1；未结发票的平均 inv_date:

    inv_id | inv_customer_id  | inv_total  | inv_date    | status
     1     |      1           |    150     | 2019-01-05  | closed (still below cost)
     3     |      1           |     90     | 2019-03-21  | open (reached total cost: 204)
     4     |      1           |      3     | 2019-04-03  | open
     7     |      1           |     99     | 2019-07-06  | open
     9     |      1           |     45     | 2019-09-02  | open

我可以尝试以下查询，但完成时间太长，而且只针对一位客户:

SELECT 
    sum_cost_total,
    SUM(inv_total_str) AS sum_inv_total ,
    FROM_UNIXTIME(AVG(UNIX_TIMESTAMP(inv_date_str))) AS avg_inv_date
FROM
(
    SELECT
        o1.inv_total AS inv_total_str, o1.inv_date AS inv_date_str,
        (
            SELECT SUM(cost_total)
            FROM company_costs 
            WHERE cost_customer_id = o1.inv_company_customer_id
        ) AS sum_cost_total 
    FROM invoices o1
    INNER JOIN 
        invoices o2 ON o2.inv_id <= o1.inv_id AND o1.inv_company_customer_id =  o2.inv_company_customer_id
    WHERE 
        o1.inv_company_customer_id = 1 AND 
        o1.inv_total > 0 
    GROUP BY
        o1.inv_id,
        o1.inv_total
    HAVING
        SUM(o2.inv_total) > sum_cost_total
) t

Answer 1

将cost & invoice分别分组，有02个子查询，然后join results得到最终结果

select cost_customer_id as customer_id, sum_cost_total, sum_inv_total, sum_inv_total- sum_cost_total as balance, avg_inv_date from (
select cost_customer_id, sum(cost_total) as sum_cost_total from
company_costs
group by cost_customer_id
) as c_total
inner join (
select inv_customer_id, sum(inv_total) as sum_inv_total, DATE_FORMAT(FROM_UNIXTIME(AVG(UNIX_TIMESTAMP(inv_date))), '%Y-%m-%d') AS avg_inv_date from
invoices 
group by inv_customer_id
) as i_total
on c_total.cost_customer_id = i_total.inv_customer_id

你应该得到这样的结果:

在需要时使用 sum_inv_total > sum_cost_total 改善条件。