SQL語句讓所有沒有訂單的客戶今天（當前日期）

Question

問題是，我該如何編寫一個聲明來使用sql join返回所有使用NO Orders TODAY的客戶？

表：TBL_MEMBER，tbl_order TBL_MEMBER包括ID，名稱， tbl_order包括ID，日期，foodOrdered

Answer 1

如果你離開加盟，選擇其中右邊的表是nulkl，它限制到

select t1.* 
from tbl_member t1 
left join tbl_member t2 
    on t1.id = t2.id -- assuming that t2.id relates to t1.id 
    and t2.date = current_date() -- today's date in mysql 
where t2.id is null 

Answer 2

假設tbl_order日期是日期時間（它可能應該是）爲SQL Server，你可以使用類似：

declare @tbl_member table 
(
id int, 
fullname varchar(50) 
) 

declare @tbl_order table 
(
id int, 
orderdate datetime, 
foodOrdered varchar(50) 
) 

INSERT INTO @tbl_member VALUES (1, 'George Washington') 
INSERT INTO @tbl_member VALUES (2, 'Abraham Lincoln') 
INSERT INTO @tbl_member VALUES (3, 'Mickey Mouse') 
INSERT INTO @tbl_member VALUES (3, 'Donald Duck') 

INSERT INTO @tbl_order VALUES (1, '2017-07-01 13:00:00', 'Fish and Chips') 
INSERT INTO @tbl_order VALUES (2, '2017-07-03 08:00:00', 'Full English') 
INSERT INTO @tbl_order VALUES (3, '2017-07-25 08:00:00', 'Veggie Burger') 
INSERT INTO @tbl_order VALUES (3, '2017-07-25 12:00:00', 'Bangers and Mash') 

SELECT id, fullname FROM @tbl_member WHERE id NOT IN 
(SELECT id FROM @tbl_order 
WHERE CAST(orderDate as date) = CAST(GETDATE() as Date)) 

不符合連接條件的行

它有助於指定使用什麼味道數據庫，因爲語法常常有細微的差別。