使用 join 仅对第一个 table 的值求和一次

Question

我有两个table

Table 1 - “B2B - 配额（直接）”Q - 每天单排

| Date (dd/mm/yyyy) | Georgina Target| Date Lookup (unix timestamp)    |
| :---------------- | :--------------| :-------------------------------|
| 1/1/22            |             | unix_timestamp(date)            |
| 2/1/22            |             | unix_timestamp(date)            |
| 3/1/22            |             | unix_timestamp(date)            |

Table 2 - “B2B - 账户到发票”A - 每天多行

| Date (dd/mm/yyyy) | Total Directs  | Date Lookup (unix timestamp)    |
| :---------------- | :--------------| :-------------------------------|
| 1/1/22            |              | unix_timestamp(date)            |
| 1/1/22            |              | unix_timestamp(date)            |
| 1/1/22            |              | unix_timestamp(date)            |
| 3/1/22            |              | unix_timestamp(date)            |
| 3/1/22            |              | unix_timestamp(date)            |
| 3/1/22            |              | unix_timestamp(date)            |

我想要return的是：

| Date (dd/mm/yyyy) | Total Directs| Georgina Target   |
| :---------------- | :----------- | :---------------  |
| 1/1/22            |           |                |
| 2/1/22            | [=13=]           |                |
| 3/1/22            |           |                |

我目前正在使用这个 SQL:

SELECT
         Q."Date" AS "Date",
         sum_if(A."Account Type"  REGEXP 'direct', A."Invoice Amount") AS "Total Directs",
         sum(Q."Georgina Target") AS "Georgina Target"
FROM "B2B - Quotas (DIRECT)" Q
LEFT OUTER JOIN "B2B - Accounts to Invoices" A ON A."Date Lookup"  = Q."Date Lookup"  
GROUP BY  "Date"

问题是 'Georgina Target' 多次求和（基于 table - “B2B - Accounts to Invoices” A 那个日期的行数）。

注意：“Total Directs”可能没有每个日期的一行，但我需要显示每个日期（基于 table“B2B - 配额（DIRECT）”）

Answer 1

SUM() total_directs 的子查询。 LEFT JOIN 和 COALESCE() 用于您的注释。假设 QUOTAS table 一个日期不能有多个目标。

SELECT
    q.date
    ,q.target --No need to aggregate since Target has a single value per day
    ,COALESCE(a.total_directs,0) -- DBMS dependent  
FROM b2b_quotas AS q
LEFT JOIN (
    SELECT
        SUM(total_directs) as total_directs
        ,date
    FROM invoices
    GROUP BY date
) AS a ON q.date = a.date

使用 join 仅对第一个 table 的值求和一次

Sum value from first table only once with join

sql

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