通过两个表格上的操作完全加入操作和分组

Question

表1

MONTH   ACCT_NUM   PRODUCT   REVENUE
Jan     9994523    VEG        50.00 
Jan     9994523    HOT DOG    40.00 
Jan     9993644    HOT DOG    35.00 
Jan     9993644    FRIES      2.00 
Jan     9996984    VEG        60.00 
Jan     9996427               15.00 

表2

MONTH   ACCT_NUM   PRODUCT   REVENUE
Feb     9994523    VEG        50.00 
Feb     9994523    HOT DOG    40.00 
Feb     9993644    HOT DOG    35.00 
Feb     9993644    FRIES      2.00 
Feb     9996984    VEG        60.00 
Feb     9996427               15.00 

预期产出

ACCT_NUM    REVENUE_TOTAL
9993644     74.00 
9994523     180.00 
9996427     30.00 
9996984     120.00 

我正在尝试在两个表上执行完全连接，并通过操作在顶部执行组。我的方法有什么问题，或者下面的查询是否有更好的方法

Q1 = SELECT T1.*
FROM Table1 T1
FULL OUTER JOIN Table2 T2 ON T1.ACCT_NUM = T2.ACCT_NUM

select distinct ACCT_NUM, sum(REVENUE) as REVENUE_TOTAL from Q1 group by ACCT_NUM

Answer 1

使用Union All。 http://sqlfiddle.com/#!6/f8e69/8

Select 
  ACCT_NUM, sum(REVENUE) REVENUE_TOTAL
From
  (
    Select ACCT_NUM, REVENUE from Table1
    Union All
    Select ACCT_NUM, REVENUE from Table2
  ) A
Group By A.ACCT_NUM

更多阅读材料:)参考：What is the difference between JOIN and UNION?

  

UNION将查询中的行放在彼此之后，而JOIN生成一个   笛卡尔积和子集......