如何從兩個表中總結兩個不同的字段與一個字段是共同的

Question

我有兩個表Sales和Charges。

表有數據爲：

'Sales'          'Charges' 
SID F_AMT       SID   C_AMT 
1  100       1    10 
1  100       1    10 
1  100       1    20 
1  200       2    20 
2  200       2    10 
2  300       3    20 
4  300       3    30 
4  300       3    10 
4  300       5    20 
4  200       5    10 

我想要的輸出如下：

SID  Total_Fees  Total_charges 
1   500    40 
2   500    30 
3   0    60 
4   1100    0 
5   0    30 

Answer 1

你可以使用條件彙總：

SELECT SID, 
     COALESCE(SUM(CASE WHEN t=1 THEN AMT END),0) AS Total_Fees, 
     COALESCE(SUM(CASE WHEN t=2 THEN AMT END),0) AS Total_Charges 
FROM (SELECT SID, F_AMT AS AMT, 1 AS t 
     FROM Sales 
     UNION ALL 
     SELECT SID, C_AMT AS AMT, 2 AS t 
     FROM Charges) sub 
GROUP BY SID 
ORDER BY SID; 

DB Fiddle Demo

Answer 2

假設你想這樣做，整個表格，這是最簡單的方法：

Select Sid 
      , Sum(f_amt) as total_fees 
      , Sum(c_amt) as total_charges 
From (select sid, f_amt, 0 as c_amt 
       From sales 
       Union all 
       select sid, 0 as f_amt, c_amt 
       From charges 
     ) 
Group by sid 

Answer 3

使用full join和nvl()：

select sid, nvl(sum(f_amt), 0) fees, nvl(sum(c_amt), 0) charges 
    from sales s 
    full join charges c using (sid) 
    group by sid 
    order by sid 

演示：

with sales(sid, f_amt) as (
    select 1, 100 from dual union all select 1, 100 from dual union all 
    select 1, 100 from dual union all select 1, 200 from dual union all 
    select 2, 200 from dual union all select 2, 300 from dual union all 
    select 4, 300 from dual union all select 4, 300 from dual union all 
    select 4, 300 from dual union all select 4, 200 from dual), 
charges (sid, c_amt) as (
    select 1, 10 from dual union all select 1, 10 from dual union all 
    select 1, 20 from dual union all select 2, 20 from dual union all 
    select 2, 10 from dual union all select 3, 20 from dual union all 
    select 3, 30 from dual union all select 3, 10 from dual union all 
    select 5, 20 from dual union all select 5, 10 from dual) 
select sid, nvl(sum(f_amt), 0) fees, nvl(sum(c_amt), 0) charges 
    from sales s 
    full join charges c using (sid) 
    group by sid 
    order by sid 

輸出：

SID  FEES CHARGES 
------ ---------- ---------- 
    1  1500  160 
    2  1000   60 
    3   0   60 
    4  1100   0 
    5   0   30