我有三個不同的表格,我在這裏存儲用戶的餘額。所以我需要的是根據日期對他的餘額進行適當的陳述。 是否有可能獲得三個不同的表上的值,並根據日期顯示它們? 如:從多個表獲取數據並按日期顯示它們
Table 1
Member = member 1
date = 1 JULY 2016
Amount = 2000
Table 2
Member = member 1
date = 5 JULY 2016
Amount = 5000
Table 3
Member = member 1
date = 10 JULY 2016
Amount = 10000
So the output should be:
Member Date Amount
Member 1 01/07/2016 2000
Member 1 05/07/2016 5000
Member 1 10/07/2016 10000
是否每個「成員」都保證在每個表中都有一行?是否有會員可能會在所有3張桌子中失蹤?你能用某種模式定義來改進問題嗎? –