使用兩列創建視圖兩張表

Question

有兩個表格：sales和expenses。 sales有兩欄：sale_date和price，費用表有兩列：date和amount。在 年也有view天。 （Create View with 365 days）

我想另外兩個列添加到這樣的觀點：在sales和 expenses表sales和expenses用數據。

例如：

SalesTable

sale_date price 

05-DEC-11 1,500 
05-DEC-11  500 
11-DEC-11  800 
17-DEC-11 2,400 

ExpensesTable

date  amount 

06-DEC-11  300 
11-DEC-11  100 
11-DEC-11  400 
15-DEC-11 1,100 

View應該創建如下

date  sales expenses 

01-JAN-11 null null 
02-JAN-11 null null 
03-JAN-11 null null 
04-JAN-11 null null 
05-JAN-11 null null 

... 


05-DEC-11 2,000 null 
06-DEC-11 null  300 
07-DEC-11 null null 
08-DEC-11 null null 
09-DEC-11 null null 
10-DEC-11 null null 
11-DEC-11  800  500 
12-DEC-11 null null 
13-DEC-11 null null 
14-DEC-11 null null 
15-DEC-11 null 1,100 
16-DEC-11 null null 
17-DEC-11 2,400 null 

... 


28-DEC-11 null  null 
29-DEC-11 null  null 
30-DEC-11 null  null 
31-DEC-11 null  null 

sales和expenses在視圖中創建的列總數爲price和amount這兩個表中的列爲sale和expenses表組爲date。

我怎麼能這樣做？

Answer 1

這應該讓你有：

SELECT the_day, price, amount 
    FROM year_days LEFT JOIN (SELECT sale_date, SUM(price) price 
           FROM sales 
          GROUP BY sale_date) ON the_day = sale_date 
       LEFT JOIN (SELECT expense_date, SUM(expenses) amount 
           FROM expenses 
          GROUP BY expense_date) ON the_day = expense_date 
ORDER BY the_day; 

THE_DAY  PRICE  AMOUNT 
--------- ---------- ---------- 
... 
01-DEC-11 
02-DEC-11 
03-DEC-11 
04-DEC-11 
05-DEC-11  2000 
06-DEC-11     300 
07-DEC-11 
08-DEC-11 
09-DEC-11 
10-DEC-11 
11-DEC-11  800  500 
12-DEC-11 
13-DEC-11 
14-DEC-11 
15-DEC-11     1100 
16-DEC-11 
17-DEC-11  2400 
18-DEC-11 
...