Question

我有这两个表：

我需要使用折扣表加入付款表。由于折扣表没有付款日期，因此预计输出似乎不可能。我只能获得net_amount

payment table:
id    |  net_amount  |  payment_dt  |  person_id
1001  |  2765.36     |  2016-05-28  |  372
1002  |  2474.76     |  2016-05-29  |  372
1003  |  22694.25    |  2016-05-29  |  384
1004  |  1911.92     |  2016-05-29  |  384

discounts table:
id |  person_id  |  gross_amount | sc_discount | other_discount_amount | other_discount_type
1  |  372        |  3566.7       | 713.34      | 88.00                 | MISC 
2  |  372        |  3202.2       | 640.44      | 87.00                 | PAT
3  |  384        |  3566.7       | 713.34      | 285.34                | MISC
4  |  384        |  27953.10     | 5590.62     | 2236.25               | PAT
5  |  384        |  2655.45      | 531.09      | 212.44                | MISC

*1 - payment_dt is 2016-05-28

expected output: (where payment_dt=2016-05-29)
total_gross_amount | total_sc_discount | total_misc_discount | total_pat_discount | total_net_amount
37,377.45          | 7475.49           | 497.78              | 2,323.25           | 27,080.93

Answer 1

正如我在两个表中看到的，共同列是person_id，您可以尝试加入它。有关更多信息，您可以考虑自然连接，在互联网上阅读它;）

＆＃34; NATURAL JOIN是一个JOIN操作，它根据要连接的两个表中的公共列为您创建隐式连接子句。公共列是两个表中具有相同名称的列。 NATURAL JOIN可以是INNER连接，LEFT OUTER连接或RIGHT OUTER连接。默认为INNER连接。＆＃34;

Answer 2

假设： net_amount = gross_amount - sc_discount - other_discount_amount

您无需在预期输出

中转到payment_net_amount的付款表

你可以这样写：

Select sum(gross_amount)  as total_gross_amount,
sum(sc_discount) as total_sc_discount,
sum(gross_amount - sc_discount - other_discount_amount) as total_net_amount
sum(CASE other_discount_type when 'MISC' THEN other_discount_amount WHEN 'PAT' THEN 0) as total_misc_discount,
sum(CASE other_discount_type when 'MISC' THEN 0 WHEN 'PAT' THEN other_discount_amount) as total_pat_discount    
from discounts

如果上述假设不正确，由于聚合完成，输出中只有1行，您可以获得除上述查询中的total_net_amount之外的所有列，从payment表中获取sum（net_amount），并加入它们只有1,1行。

两个表的SQL总和

2 个答案: